Olysik

You are very welcome.  There are times that this process will completely stress you out.  Stay focused on your partner and your love.  This is not meant to be quick or easy.  Smile and make sure all the paperwork is correct.  Have all the required back up and make sure every checkmark is complete and correct.  That is the best way to make this as quick as possible.
 
Please fill out and correct your timeline.  That way we will know where you are at.  

As @Naes says, please dont ask the same question many times.  The real answer will always be the same.  
Please fill in your timeline and we will all have a better understanding as to where you are in the process.  You can join the thread of the month that you got you NOA1 and track things much better there.
 
Naes is right on.  My NOA2 took over 9 months and some are here waiting over 10 months.  Things are moving much better now but 6 to 7 months for NOA2 is a great starting point.  4 is a pipe dream I'm afraid.  Expect the entire journey to POE to be 9 to 12 months.
 

You are asking almost the same question everywhere. However you already got a good answer when you first asked. The answer is not really a flex answer.
 
waiting times at the moment are 6-7 months. It can be longer because each case is different. However times are improving so it can get shorther by the time you get it.  
 
Zip code system does not work on k1 cases. 
 
Processing time for california is at least 6 months. They are just doing - August - September  cases and some people in June and July also waiting.
 
 
 

217 days.

All k1 petitions go to California service center. a transfer may occur from California to Vermont in rare cases (usually awa or domestic violence etc. past of the petitioner)

Of course. A lot of people travel back to see their fiance(e)s during the process. I traveled a couple times for work. Doesn't matter at all. You're a USC, you can do whatever you want.
Same as the beneficiary can travel to the US if they can even during the process.

People on here have different dates on when they have been filing K1s or other visas - so our dates will typically look a lot different from what is going on now. 
If you look at current processing times: 
http://www.visajourney.com/content/k1historical
 
You'll see that the current average for the approval (known as NOA2) is about 196 days. After the approval process - your case goes to the NVC, which sometimes takes a few weeks, then to your individual consulate which also takes a few weeks. the only variability is on scheduling the interview. If you fill out your profile - it will connect you to a portal for the country/consulate you are dealing with, where you can reach out to others and see their timelines and how long it took them to get an interview. 
 
The portal for Ukraine is here: http://www.visajourney.com/portals/index.php?country=Ukraine
 
A good average for a timeline is around 10 months for processing from start to finish. 
Remember that there are many benefits to marrying and filing a CR1. In the "old days" (aka - a few years ago) a K1 petition was taking about 4 months from start to finish - now it's significantly longer. Add on to it the adjustment of status (currently taking 4-6 months after marriage and filing) and the inability of the beneficiary to work/travel and sometimes even drive until all that takes place and you will see that the CR1 is a far superior visa with only slightly longer processing times (currently 12-14 months start to finish). 
 
You may want to consider this as a possibility too.