Withdraw 401k amount

Most of your questions need to be answered by the plan.  

The most likely answers are:

1) unlikely...  my guess is the best way to do this is put it in an IRA which would allow you to control how much comes out of the IRA.

2) Since #1 is most likely no this is n/a

3) If you terminate it is unlikely they will allow you to take a loan.  If you have a loan and terminate that will trigger the loan to become a distribution.   Your company ought to be able to get you more information on that.   But what I describe is how 99% of all plans work.  

You need to talk to your company to get the correct answers as they can be plan specific.   The above are the most likely answers except for #3 which is pretty much how all 401(k) plans work.

You will need to do a good amount of research on taxes, the withholding rules and these kinds of distributions.   The withholding rules are complex.   This will be US income if you take a distribution.   So you will have to keep filing US tax returns if you take the money out of the 401k or IRA over a number of years.   If you really have $100k you need to stop looking for free advice and spend some money on a good tax accountant.   Free advice is worth what you pay for it.  In this case spending some money on a good tax accountant will almost certainly pay for itself by saving you time, trouble and maybe taxes.   I would look for someone who really understands taxes for people living outside the US and retirement plans.