No he wasn't. For the season you're referring to - Marco Reus was the Bundesliga player of the year.
http://www.uefa.com/memberassociations/association=ger/news/newsid=1838840.html for 2011/ 2012.
Kagawa was only a fictional Bundesliga player of the year for shite websites including the ever reliable daily mail :
Not one time but twice. Good job Daily Mail.
http://www.dailymail.co.uk/sport/fo...rid--reveals-Jose-Mourinho.html#ixzz3CI7RST8m
As for the rest of the post :
1. Yes he did. His role under De Boer was as a #6 and Blind was excellent. Nothing flashy but the most effective #6s aren't supposed to be flashy. Just look at the best CDM of his generation - Sergio Busquets.
2. Patty Evra is 5'7" and was torn to shreds in his debut appearance. De Gea was a stickinsect when he first arrived at United. But both of them went on to have great careers. I don't think the physicality part will make much of a difference for an intelligent player like Daley when people like Mata or Silva can play at the highest level. And apart from a little lack of pace Blind isn't physically weak.
3. Can I borrow the crystal ball ? Pretty please ?
4. Blind has a great first touch, good awareness, tacticaly astute, technically proficient and has a good passing range bordering on very good at times. He played brilliantly when Ajax faced one of the best pressing teams in modern football Barcelona and beat them, also did really well vs another great hound press team in Dortmund. He'll do the same in the Premier League.
5. About the rest I wouldn't say much because admittedly you've only seen a few matches and youtube videos. It's not a good enough sample size. But even then Blind was one of the revelations of this World Cup - gave 3 assists and scored 1, playing in a mainly LWB and LCB position - not his first choice position anymore. I dunno the last time Cleverley did that TBH. Also his great technique and tactical knowledge was on display throughout the tournament.
Blind will be a good player for United. He may struggle a bit at first but like most intelligent players he'll adapt. If he wasn't then Van Gaal wouldn't have bought him.