US Immigration from Philippines

TL;DR

I'm going to the Philippines in a few months to marry my girlfriend. For the sake of "bonafide marriage" is there a certain amount of time I have to be in the country?

Longer details:

We've currently applied for the K-1 visa, and I already bought a 2-week summer trip to visit her. Then, we decided to change to CR-1 instead and plan to get married during my summer trip. She did some research and it turns out it takes about 2 weeks for the marriage certificate to be processed and advised I should stay an additional week.

I'm kind of resistant to the idea because airplane prices have gone up, my workplace might give me some trouble, etc. But if it's essential, then I'm definitely going to do it.

Just wanted to hear other people's past experiences to help me make a guided decision.

Okay, so my Fiance is 21 and I am 65. I know this is a huge age gap however in the Philippines age is not the deciding factor for young ladies. Does the US Embassy know this or are they going to give her/us extreme scrutiny at the interview? How do we prepare for this? We have provided evidence with our initial filing of us being together in the Philippines. We have provided evidence of our engagement, including the Manager of the Hotel who wrote a letter, on hotel letterhead and stated that he was present at the engagement surprise. We have provided photos together holding up 4 newspapers with the dates on them. I also provided my boarding passes, etc... I know the age gap is huge and maybe I am crazy but I believe that my fiance loves me just as much as I love her.

(In 2013 I went to the Philippines and married a 19 year old girl and brought her to the US. She walked out on me after 8 years of marriage and two children. I never saw it coming.) Our divorce was finalized in January 2021. I knew I could not marry in the Philippines again as they do not recognize US Divorce, hence the K-1 visa this time. Tell me, am I crazy?

My stepdaughter would like to become a citizen. She and her mom (my wife) arrived 5 years ago. However, it took about 15 months for them to receive their green cards. The rule for Form N-400 states that you must be a permanent resident for 5 years for my daughter (3 for wife). Did my daughter become a permanent resident when she arrived in the US or ONLY after receiving her green card. That's important to know so her N-400 doesn't get rejected. I did a lot of google searches but couldn't find an answer. Thanks in advance.

We got my wife here from the Philippines last year, and started the process for her son. We're nearing the end, as he has his embassy interview next week. We got a long, automated email from NVC with a list of things to do/check, and one of them is "be sure you paid your fee."

> Immigrant visa applicants who have not paid the visa processing fee at the National Visa Center should pay with the Embassy s Consular Cashier. The schedule of fees is available at https://travel.state.gov/content/travel/en/us-visas/visa-information-resources/fees/fees-visa-services.html.

Are they referring to the fee that we paid at the start of this for her son? Or are they talking about some other fee incurred close to the end of the process? How do I see if I've already paid? Or should I just not worry about it, and pay them with a CC on the day of the interview if they ask for it?