Cyber Stein still is way too OTK making though. 5000 LP is a steep cost, but LP don't matter if you're going to win that turn. Back when it was Banned you would just summon Blue Eyes Ultimate or something and use Megamorph and that is an OTK right there. It would be less dangerous now what with all the counters to everything and Veiler and such but still can't see that happening.
Thousand Eyes Restrict on the other hand very possible. The thing people used to do with that was with Tsukyomi I think and that combo is way too slow nowadays. But true, there is Instant Fusion now...so I dunno.
Burial makes Mezuki, Plague, Vayu and future cards that use the same mechanic essentially free. I think Zombies and Vayu Turbo were reasons.
Huh. This is a pretty neat place for questions such as yours:
http://yugioh.wikia.com/wiki/Forum:Reasons_why_cards_are_Forbidden/Limited