Yes. In my opinion. Harry does not use Bob as he should. I suppose it is because JB does not want to make things easy for Harry. But so many things he should ask...
And yes, it would be fun to ask Bob because he probably would add some fun and personality to his answers.

I like that Dresden in a nutshell.

Again, we don't know. My feeling is, no, the mantle would not leave Mab unless she somehow can shake it, which I don't think is possible (unless very specific circumstances happen, at least)

MAEN!
Welcome to the boards 
I have disappointing news for you. As far as I know, the answer to your question is a "no". At least, I am sure that JB himself does not do that, and I did not hear of any account doing it. I am sorry. But you could ask a question in the DF Spoilers section and ask the community to tell you what they think that Dresden's answer would be. I believe it could be fun! Of course, if you had not read all the books, ask the question in the DF books section, not the spoiler one, and make clear in the first post until what book you have read.

I agree. If I understand correctly, human identity changes much than, for example, Mab's identity (Uriel would be an even more extreme example).  In fact, I am wondering if perhaps the Names that Chauncy got for Harry are not so usefur right now.

I think Harry explains somewhere that as you cannot use old blood for humans, because humans change, something similar but slower happens with the Name. Perhaps even if someone has no change his legal name, they can change the way they say it, so changing the Name.

Welcome back!
I think I understand what you are saying about Twelve Months but I personally had no problems with that.