Please, some advices.

[darktyroll]

Can you guys help me with some problems please? I`m new with this phone i have 2 days, my old phone was with android too but with this one some things are different. So, i really need to know:

- right now i have 2.34.1 in my Defy, if i make update to 2.51.1 i can be back to 2.34.1 after?
- to update to 2.2.* i need to be with 2.51.1 of i can flash over 2.34.1?
- what is the original recovery and boot for 2.34.1?
- with defy_recovery-1218-0326-signed.apk i can make backup to original 2.34.1?
- if in case i need warranty i can flash the original recovery?
- what are modes and button combinations to start phone (like recovery, hard reset, etc)