Epmp Force 200

I have some questions ?

1. Can I make software update for force 200 when it is on Eptp mode or it is available only on SM mode?
2. Can I update  from Software Release 2.1 to newest one directily or I have to update it step by step ?
3. When I am doing restar after that  I can't login with default username and password , does it changes after I make radio from SM to Eptp mode?
4. And last one what is difference between TDD and TDD PTP  mode for using force 200 as AP