1) Nah. Though my favorite "monster" was the first two appearances of the weeping angels. I like to pretend the episode with the giant weeping angel didn't happen--it was a little ridiculous.
2) David Tennant, hands down. Though granted, I've only seen the 1996 movie and series starting in 2005. I haven't seen any of the classic episodes.
3) No idea...there aren't enough clues to speculate on that, IMHO.
4) It was ok. I was half expecting to see some explanation as to what the [Nightmare Child,the [URL="http://tardis.wikia.com/wiki/Horde_of_Travesties"]Horde of Travesties, the [URL="http://tardis.wikia.com/wiki/Skaro_Degradations"]Skaro Degradations and the [URL="http://tardis.wikia.com/wiki/Army_of_Meanwhiles_and_Neverweres"]Army of Meanwhiles and Neverweres led by the [URL="http://tardis.wikia.com/wiki/Could%27ve_Been_King"]Could've Been King](http://tardis.wikia.com/wiki/Nightmare_Child) actually were, which seemed to be the reason why the time war was time locked. The time war didn't really seem all that epic, which was a little disappointing. It was mainly about the three doctors standing around, chatting it up, and sounding all clever and whatnot.