CCF at the garage ceiling, whether for the entire insulation, or as a perfect air seal, will give you an immediate payback in terms of comfort, both in winter and summer.

Unless you're planning to heat the garage, the insulation in the exterior walls is unnecessary.

You didn't say what point your build is at. One of the most effective things is to put rigid foam outside your sheathing, under your siding. Even one inch is enough to break the thermal transfer through the studs. If you go this route, tape all of the seams to eliminate air infiltration.

Make sure you look in to insulating around the perimeter and the bottom side of your slab if you are doing radiant heating.

it actually appears you have a pretty decent handle on your needs for your climate zone. Most cases people post here "doing 2x6 frame walls with fiberglass for high energy efficiency". That is highly laughable.

The best "bang for buck" insulation is cellulose, by far. Not only is it much greener, but its more dense (sound deadening, helps to reduce more thermal transfer vs fiberglass, borate treated, and more fire resistant). Do not focus on r alone. Blown blanket will have a slightly higher r (typically around 4.1) vs dense packs or wet spray cellulose (around 3.9ish). However due to the density of cellulose, it will out perform blown blanket any day of the week in the other areas. fiberglass also reduces r when temps drop. Cellulose is also typically slightly cheaper then blown fiberglass. I would have them look into wet spraying or dense packing cellulose in your wall instead of blown blanket. Also definitely get a price to blow cellulose into the ceiling instead of fiberglass. You should not only reduce price slightly, but also have a better performing product.

Also notes, if you can put a 1" layer of XPS on the exterior of your house, that will greatly increase your thermal performance of your walls. example: using a r-4 roughly, you are sitting at r-22 center of cavity. Reduce that by a framing factor of 20% as well as *some* infiltration, you are closer to an r-14 range. Adding the XPS has you sitting at an r-27, with infiltration even more reduced, and your framing factor is reduced to closer to 8-10%, giving you closer to a CLEAR WALL of around r-20-23. Around here XPS goes for about $.78/sqft plus install, so just under a buck a square foot.

Air sealing however if your #1 priority. This makes a huge difference. It sounds like you are ahead of the game there though. Caulk anything and everything. Sills, headers, sheathing to face of studs, etc. Caulk is the cheapest way to make the most difference on your new build. If you really want to take it to the next level, after your shell is up, windows in and attic sealed (BEFORE insulation), have someone come do a blower door test. This will help find leaks and other areas you can easily fill prior to insulating.
Also consider air tight drywalling and a secondary air infiltration barrier.

So off of that rant, back to your ceilings. What exactly is "flat part of the ceiling?"

I would NOT recommend CCf in your roof. I always recommend or spec open cell. R is not quite as high, but the perms are much lower then CCf. This, IMO, is important especially for roofs. If your roof develops a leak, how will you know? Close cell will allow the water to sit there on the foam, pooled on the underside of your sheathing rotting it out from the bottom up. What is worse it can start eating away at your joists as well. Open will also be about 1/3 of the price of closed. So I would fill your garage ceiling completely with open cell, and then if funds allow, fill your bonus room with open cell as well. Worse case use open cell to create your 1" air seal, then do wet spray cellulose from there. However keep in mind with expanding foams...the first inch is the most expensive. The next few inches cost pennys compared to that first inch.
However DO have them fill your rim joist area completely with open cell. This should only cost around 500, but will be worth it. this is one of the most leaky areas of the house that gets the most neglected.

Finally, I disagree with the recommendation to skip the batts in the garage. However I will recommend r-19 instead of r-21. Again, do not always focus on r values. those are derived from steady state numbers, but real world performance tests shows they perform nearly identical. R21 has a large increase in cost vs r19.
I think it should stay because, even though the garage is not directly heated (I assume)you will still have heat transfer, loss, and generation within the garage. With a heated space above and to the side of the garage, insulated walls will help buffer your heat losses in the conditioned spaces. The cost for r-19 batts in probably all of a few hundred bucks depending on the size of your garage.

Thank you all who responded...and so quickly! We, sadly, are past the point of being able to do rigid on the outside of house. The house has been sided, roofed (asphalt shingles) and windows are in. Lzerarc, I believe I first got the idea of caulking EVERYTHING possible from you here on Gardenweb. I owe you a debt of gratitude!
The 'flat ceilings not accessible to blow crew' is a small area above the master bath. It would otherwise be the unfaced batts for combined r49....at only an additional $300.00+ I thought that Rigid might be the way to go there?....
Lzerarc, re: getting a door blower test, what do you mean by 'and attic sealed?' Also, what do you mean by 'a secondary air infiltration barrier?' Lastly, (promise!), thoughts on the '1" Rigid as baffle at joisted vaults and scissor vaults?' It would, I think, otherwise be r-38 unfaced batts. Worth the additional $1721.00?
Will get a bid then, for the cellulose and open cell foam and filling the rim joist area.......
My apologies if my message is tedious! I have asked a lot of questions of different insulation contractors, but none explain things in a way I seem to understand. Thank you Gardenwebers!!....

DD- googl "airtight drywall". That should answer all of your questions. Its just another step to seal up the house from the little air that does get through. Successful ATD installs have cut infiltration up to nearly 1/3 more.

For the rigid, do you mean install 2' strips inside the I joist- joists all the way up the peak giving you a 1.5" air space? Or do you mean they will use it as the insulation dam and notch around all of them? Sorry, not really understanding what they are after.