Jim,
Actually, it isn't really hard to get lumpsum payment now from TSP, I had changed my fixed payment and then subsequently requested 2 lump sum payments...the last one I got in one day.
Rollovers take longer and the address has to be be on file one week in advance. I had them send the check to me in name of brokerage and the overnighted it to brokerage in prepaid FedEx rather than wait a week. Still worked the same as institution to institution transfer.
You have to have earned income (W-2 or Schedule C/Self Employment) to contribute to Roth, but you can do conversions and pay the taxes. There are also 5 year rules applicable to Roth that you should be aware of if you have all your retirement funds in traditional accounts.
TSP used to have a great calculator that combined SEPP/Life Expectancy and RMDs but there new tools are worthless. I end up using a spreadsheet & the IRS factors to calculate but this RMD calculator gives you a pretty good idea of what your RMD payments will be if you don't start taking withdrawals.
https://www.calculator.net/rmd-calculat ... #calresult. I was going to pull back on withdrawals from TSP this year but this convinced me that I need to take out at least the Life Expectancy amount. If you don't need the money, you can invest in regular brokerage or convert to Roth