Merrytooth

Spending half your time in the US is a red flag. Don't play semantics with the two weeks more in Sweden than the US.
If you have a valid F-1 visa, you should have no problem entering the US.
Don't lie to CBP. You've already told them that you have a US boyfriend. They record things like that. You need to tell the truth. Lying or omitting facts will hurt your credibility and you could be denied entry.

So if you need medical help, who should pay for you? Go home and wait to die?

You may have a different understanding but I can speak from experience that a previous filing followed us all the way
into the AOS interview with a stokes for an hour each asking about my previous petition that happened 10 years ago.
Not to mention that the general consensus on VJ is to write a timeline and one of the reasons being this exact
circumstance. Unless you work as an IO or CO your opinion as a public administrator is not relevant.
Apples and oranges.
Different CO's have different thoughts and will exercise their power of discretion differently, reach a conclusion and want USCIS
to consider something they see so they return the case.
If a timeline is written it will clarify things for the CO and he likely decides USCIS has seen this already, no reason for a return.
OP would likely be asked why he thinks a third time is a charm. USCIS will have already seen it.
You may not have had a problem yet but that doesn't mean you will not or others will not have a problem.
We had a stokes with the embassy (with me on the phone) and at AOS and everything centered on an approved
10 year old petition and the person never even made it here.
Understand that just because you had no problem so far does not mean OP won't and a timeline narrating his current
relationship and touching on the previous relationships is strongly advised even by immigration attorneys.
The letter can not be any rambling but a clear precise overview from all petitions with names, dates and case numbers.
No embassy will take 3 petitions lightly. Not even yours.

The dog peed on the bed.

I disagree. Being open and transparent from the beginning with USCIS by writing a relationship timeline
is good to do. The CO then can not say "USCIS was not aware of this information so I have to send it back."
Once USCIS has seen it all in a front loaded petition with relationship timeline it will be in your favor.
Of course the CO could still have issues with it and return it but not for the reason of "USCIS did not see this or that."

Don't see how the ex can claim you as a dependent if you're covering everything yourself.

i went through the K1 process, simply do not believe she could have done clueless.

Or 3 years to fall in love with a USC

My husband (USC, also PhD in ChemEng, used to live/work in Texas) says that 99 % of jobs are filled through networks. His advices are to attend career fairs, reach out to companies and ask for "informational interviews", reach out to professors in the area and ask for insights (since they usually have knowledge of who is hiring). One way or another you need to get past HR, since they will rate your all-foreign education and experience low. Good luck, Texas should be an eldorado for someone in your profession!

You have gone to great lengths here to tell us how genuine this marriage is. But it's not us you need to convince. It's USCIS and the consular officer at the interview. Obviously you failed to convince the consular officer.
You seem to (wrongly) think that because you have not done anything illegal your wife cannot be denied a visa. You even have evidence in the form of a 221g in front of you that visas can be denied even if the parties have not broken any law. Immigration is a privilege. No one is guaranteed a visa ever. Having seen much stronger and more convincing cases be denied here, frankly I'm not surprised that your wife's case was denied.
Now, since you clearly love your wife dearly and cannot bear to be apart from her I would suggest you apply for jobs in India and go back and live with her there. After all, the ultimate aim of all this is to be together and not move to the USA. I tried to bring my husband into my country and we were denied. So I have moved to his country. It's what you do.

Merry Christmas!

I-129F Part 3 Questions 2a, 2b, 2c ask for the crimes committed.
30+ criminal records - is the USC able to hold down a stable job?
Will your friend (given her conditions Austism, Heart Issues) be able to survive on her own in US should anything happen -> relationship breaks down?
I would suggest to proceed with caution.

The age gap is a hurdle for sure, but with enough evidence (such as plenty of face time, meaning time spent in the same space) it can be overcome. VJ has enough such stories, which you can search and read about -- so age difference alone is not a predictor of visa denial.
Living with your ex-wife, being out of a job and having your ex-wife support and co-sponsor you might be pushing the limits of what one can overcome. Your current life as it is would be scrutinized by most any CO, so I do not think this is country/tradition specific, though you also have that going for you.
I suggest you make a better game plan, get a job, keep the job, move out, start saving money, file your taxes and start a new life on your own first, then you can think of bringing your wife to the US.

Your ex wife is claiming you as a dependent for tax purposes? Living like roommates yet divorced?
You're unemployed and ex-wife is co-sponsor?
New bride is 19 1/2 but married for close to two years.
Yeah, no idea why they denied your wife.

polygamy?
just seems very odd that your ex wife that you are living with would sponsor your new wife. though technicaly you are not since you divorced your third wife you are still living with her and your fourth wife will soon live in the same house. I would suggest getting a job and moving out so you can live with your fourth wife and move on from your third wife.

There is something very strange about a 46yo, thrice divorced man secretly marrying a foreign 17yo girl (were you dating her at 16?) while cohabitating with one of his exwives who financially supports him as he is unemployed. Take the time to mull that over.

I-129F Part 3 Questions 2a, 2b, 2c ask for the crimes committed.
30+ criminal records - is the USC able to hold down a stable job?
Will your friend (given her conditions Austism, Heart Issues) be able to survive on her own in US should anything happen -> relationship breaks down?
I would suggest to proceed with caution.

I-129F Part 3 Questions 2a, 2b, 2c ask for the crimes committed.
30+ criminal records - is the USC able to hold down a stable job?
Will your friend (given her conditions Austism, Heart Issues) be able to survive on her own in US should anything happen -> relationship breaks down?
I would suggest to proceed with caution.

What I have learned about people who are new to the process is that the first thing they are interested in is time (or speed of getting visa). Overall cost, from beginning to end, is a distant afterthought..

I-129F Part 3 Questions 2a, 2b, 2c ask for the crimes committed.
30+ criminal records - is the USC able to hold down a stable job?
Will your friend (given her conditions Austism, Heart Issues) be able to survive on her own in US should anything happen -> relationship breaks down?
I would suggest to proceed with caution.

I-129F Part 3 Questions 2a, 2b, 2c ask for the crimes committed.
30+ criminal records - is the USC able to hold down a stable job?
Will your friend (given her conditions Austism, Heart Issues) be able to survive on her own in US should anything happen -> relationship breaks down?
I would suggest to proceed with caution.

I-129F Part 3 Questions 2a, 2b, 2c ask for the crimes committed.
30+ criminal records - is the USC able to hold down a stable job?
Will your friend (given her conditions Austism, Heart Issues) be able to survive on her own in US should anything happen -> relationship breaks down?
I would suggest to proceed with caution.

I actually enjoyed the 3 months of doing 'nothing'
Watching cable TV, napping, walking the dog, going grocery shopping nearby with a bicycle,
eating ice-cream all I want, reading books from library .... etc
In fact, I felt time passed very fast.
Once you start working, you will realize how little vacation days you get in US.

No.
You will need to pursue a spousal visa from outside the US, assuming you're already married.
Expect the process to take around a year.
The I-485+I-765+I-131 you filed is now considered automatically abandoned by USCIS.
If you were previously a DACA beneficiary then you may have inadmissibilities to deal with too, depending on whether you had any prior overstay before you were approved for DACA, how long that overstay was, and at what age you were granted DACA.

He will need EAD or green card to renew the driver license.