If it betters the wiki, I'm all for it. I am concerned about some of the same things in the "cons" section that you are, namely takeover and vandalism (as if some people don't wank enough about the wiki on LJ and elsewhere, whether it's for something understandable like the old human-name format or the sillier things like who's running it).
But the new layout is a literal eyesore, it's hard to see some of the pages and the colors are blinding as it is. I won't be too sad about blogs going I guess, they were handy but kind of brought embarrassment when they'd show up in Google results for Hetalia or country stuff XD
A forum could really help, but we'd probably need some way to weed out trolls too. I'm for Kitayume wiki being moved too. By the way, you guys might have guessed it, but I'm Black-Noto there too. I confess! I've never sockpuppeted here with it though except asking Lilly a question on the templates (and forgot to log out of that one). I'm not sure how the transfer will work for both wikis though, so I'm not sure if it'll be necessary to have the dual account still. Guess we'll see.