Robben is a great player, but he had a lot of injuries this last year or so. As you say, I'd have pushed to include him in the deal.
I suspect the Mancs will be sronger without Ronaldo, in the long run, though not necessarily straight away.
Taggart is tactically poor and could never have got the best out of the player, once Queiroz left. A lot of games this season they've won due to individual quality, in spite of the tactics they've tried to use.
I expect to see them putting out a much more traditional 4 4 2, which is all Whisky Nose is really good at. Can't see who they are going to sign for the holding midfield roll, though. Says a lot that Fletcher is their best player in that position. He's a good player, but not top notch.