12. Can I stop/start/change at any time?
Details are not finalized yet, but you will likely be limited to starting, stopping or changing (for example, redistributing your money among the different mutual funds) to "open seasons" once or twice a year.
13. When can I take it out, without penalty, before age 59 ??
When you leave the Service, you may "roll" the account into an IRA (Individual Retirement Account) or other qualified retirement plan. Other than that, you can not withdraw it without paying taxes and penalties before age 59 ?. You may, however, borrow against your TSP accounts at very favorable rates. These loans may be used to pay for cars, purchase a home, or meet a personal need for extra cash.
14. Is there any impact on retirees? Can part of retired pay be put into TSP?
No, retired pay may not be put in TSP.