Im no full timer but i think ive improved quite a bit over the last few weeks and i 3 table at the lowest stakes on bodog, which gives me 20$-40$ an hour, which is pretty nice i think when you compare to the recommended 100$ an hour if you wanna go full time.
I definitely think that if the games you play in are fishy enough and you can handle the pressure, eight tabling can be pretty managable and profitable. I would recommend full table (not 6-handed) though for eight tables as shorthanded play requires much more attention than a full ring game.
As for studying you might want to check www.cardrunners.com for their videos, theyre pretty useful in mastering the shorthanded game. Or if you dont want to spend any money on those you can still check http://www.pokertips.org/videos/videos.php which contains some nice videos too.
That kind of material helped me improve my play a great lot because they show actual sessions without cutting out the bad plays and boaring moments you get when you actually play. I usually read poker articles if im bored or just want to chill with a full ring game in the background, it cant make your play worse to study other people's look on the game.
Hoped it helped you gl and see you at the table.