Hmmm....Well fat support is there in all Linux distros. IN some distros like Ubuntu where it mounts all the fat partitions already, u have to configure it to make it write also to fat partitions.
Its good as default becoz if u r a noobie then by any chance u may delete folders (system folders that is) on fat partitions messing the windows completely. Neways u r right. Cutomization is there n good and even tiniest thing can be customised!
Neways just like to all noobies, I suggest u stick to one popular distro first. Also if u like customising that much, then I suggest u install
fluxbox. U can make ur desktop look way better than kde or gnome with it.