There've been really too many major changes to list, that's why I haven't listed a more complete list. In many ways, it's a completely seperate game than the 7DRL. There are standard armor and weapon slots now, different classes and skills, different weapon and armor types, ranged weapons, different categories of spells, pets for necromancers, a fully featured town, saving and loading, chests that you can put stuff in, cursed weapons, rings, scrolls, dungeon "traps" like wells, unique special abilities for every class, a host of unique dungeon levels. It's really a much more fully featured roguelike now. Soon, I'll put up a youtube video that shows it off.
The payment is handled through BMT Micro, which is a pretty common payment handling system for shareware. You order from them, and they give you the registration code. In game, it links you to the order form from the main menu, and also when you encounter stairs leading deeper than the first level.