Spend some time researching installing ROMS and backing up your phone (making nandroid backups as well as Titanium backups and even about sbf'ing). You need to know more before you go farther. You didn't know your apps would disappear, or understand why your pictures were still on your phone (on the sd card) after flashing a ROM. It's great that your adventurous and want to get the most from your phone, but if you don't understand more about what's happening, your going to end up with a 4.3 inch paper weight.