good post, even though i may not agree with everything you wrote.
one thing i will comment on is that you say he needs to change if he is gunna be a force in the hw division(which he kinda already is ) he will need to change. my answer to this is, he is, he is changing almost everything about himself in a somewhat drastic fashion. the thing with mir is that even though he talks allot of crap he is smart he realized the way he was he was going to have trouble with the evolving/de-evolving (however you want to look at it) HW division, so he bulked up drastically in a smart way and has worked on his striking witch has improved allot. honestly with the he needs to work on his takedown defense statement, this i think he should not worry about to much for honestly a fighter can work on takedown defense all he wants but lesner will take them down at will everytime
i don't think the heavy emphasis on striking for Mir is the right path. Sure, it won't hurt to be a better striker, but that's not the tool that will help his chances the most against Brock. He needs to work on his wrestling and using the cage to his advantage like Randy did against Brock.
We'll see about his size, but size doesn't equate to functional strength. Brock has insane functional strength, and Mir will never beat him in this department.
I respect your opinion about spending time working on TDD. If that's the case, then he needs to work on his take downs and transitions so he can get dominant positions. IMO, he came into UFC100 underprepared and with the wrong game plan. Yes, he admitted this, but I don't think he'll have the right plan (putting on mass and furthering his striking) going into Mir/Lesnar III.