[masetas]

? 1a) Yes you can drag and drop into a window like you can with a USB once you connect your phone to your pc you choose "mass storage" and you get the window on your pc. You can drag and drop any file on it.

2) Yes as well directly from phone no need for pc (atleast for me) as well as to twitter,send by bluetooth, mms, email etc...
2a) Camera i believe records in 720

3) Sd card is 16gb dont think you need more memory capacity but regardless yes you can easily too just remove the back cover and there it is.

4) no problems,

5) should be able too

Customize? depends how much customization you want to do. I.e. change launchers,docks in launchers, some themes, wallpaper basic stuff yes no unlock required.

Fear of Samsung? Only issue with this phone has been Samsung/Sprint not giving us the upgrades we want as quick as we want i.e. Froyo or gingerbread.

Hope this helps