Good post. I'll respond to the second one after I've had time to ask what I want to ask on your first.
1) As far as accurate OOBs goes, I love to hear what you and others say needs to be "tweaked".
First off, I do understand the software limitations, limited slots, etc. I think it's a great idea to move things like the SturmTiger, Uhu, and other rarities to another country's OOB with more room (using the German example). Makes complete sense
provided their "new" location is known. I'd like to know where they are in the instance I'd like to buy a SturmTiger for a late-war scenario (however rare).
Secondly, changing the OOBs and units within them is difficult, but not impossible (reference all the work Pz Leo's crew has done). I'm not sure if this would solve the problem of trucks you referenced, but hear me out, tell me what you think. And yes, pack a lunch, I want to address each of the OOB problems you've addressed because I think they're valid concerns. Is there a separate movement class for "multi-wheel-drive" (for example, Armored Cars, thinking specifically of the 8-wheeled GE ones) vehicles and standard wheeled vehicles?
If so, add mobility to the multi-wheeled if need be, tweak the "standard" so that roads and open fields are easy, woods are a challenge, and simply re-class the "high-performance" and "lower-performance" trucks into the two categories. Perhaps you could even use the category for wagons or horse gun teams in terms of mobility. I don't know the mechanics as well as I'd like, but there has to be a workaround for your truck mobility issue you raise.
Thirdly, as far as the Krupp, that's just a simple change, isn't it? Tweak the (towable gun and passenger) carrying numbers to make it suit. Out of curiosity though, if it was made to tow artillery, where did the artillery crews ride? Did they run beside? I don't think that a lack of plush seating would deter them. Look at Tankodesantniki, just a handhold and it's "all aboard!"

I think if it could carry 7 crewmen for it's 7-man artillery (as you cite), it could carry a squad of 7 infantry all the same, albeit historically inaccurate. Hell, I would rather use an Opel anyway, larger capacity, cheaper, and IIRC faster. On that note though, is the Krupp icon/gif wrong? Could the above changes make trucks more realistic across the board in the OOBs? Are they technically possible? If so, we've waited until the 11th hour to discuss this, but perhaps we could see those changes in 8.1

.
3) With regard to overall accurate OOBs that serve as an accurate purchase pool for the AI as well, what do you think about using a combination of "Rarity" and the shifting of
special and unique equipment to other Nation's OOBs as a means to remedy this problem? Although I dislike the function personally (only because it doesn't reset if you delete an item off), I think it makes things much more realistic.
My problem with "Rarity" is that when I'm making my buys, I'll look at the map, and try and figure out what units specifically I'll need for that battle. I may change tactics as I plan in my head, deleting some units, adding others before I'm finally satisfied. The problem comes when I purchase a
more rare unit, it disappears from the Purchase menu because of its rarity (as do other "rare" units simultaneously IIRC). What if I decide I don't want it though? I sell it back, but the "Rarity" counter doesn't reset, so now I can't get that unit should I change my mind again, or another rare unit. If that were fixed, I think "Rarity ON" would be one great way to prevent nothing but Panther Gs and Konstigers in your next AI battle, and moving the
more rare units would cancel out the 5 SturmTigers. Again, what do you think of this? Would it alleviate the current problem as you see it? Is it technically possible?
In addition, if the Germans/US had less Halftracks than we currently see purchased, couldn't "Rarity" also be used to mitigate both infantry and artillery transport vehicles? Imagine "oops! Can't buy any more SkdFz 7's, gotta get horses now

". Ideal? No. But realistic and more challenging? Yes, as long as it's not unilateral, but that's a balance issue.
4) Artillery. I didn't know that it's currently still that off. I must admit I have done zero historical research. Is a 1 turn delay compared to a 4 turn delay genuinely realistic? A 4-turn delay IMO would make artillery almost useless unless in the defense, where the enemy was tied up in a minefield, or for on-board counterbattery with a lazy opponent.

How about a 0.5 for the US (which could be lowered further by experienced FO/Arty crews) 1.0 for the UK, and 1.5 for GE/SO? Harsh enough? And would small mortars be an exception? (11B not 11C here :p). I do like the concept of a somewhat extended delay. That would honestly be really neat/challenging. But one thing that'd have to remain is the short time for pre-plots (gold stars). All countries could do that and fire rapidly. They'd become KEY for artillery usage then.
5) Now, what I think is your last point of contention in the first of the two posts, that of maneuver. I like the idea you bring up of BN-size elements as the primary C&C/execution organization. However, I don't see it as difficult to recreate using current OOBs and the purchase options therein. I do think a few changes could be made to even enhance it though.
Currently, you have the option of purchasing Companies of infantry of differing types (again, using GE as an example, sorry if that rubs you the wrong way, just the OOB I'm most familiar with because of all those WWII campaigns long ago). You could pick a Pz Pioneer Kp, Grenadier Kp, etc. The only piece of the infantry pie that's missing is telling the player how many companies were included in the BN's typical MTO&E, that and enough space to deploy all of them

. You could then purchase the artillery typically included (again you could tweak each Country's OOB a little so that the Artillery included "Company-size" distributions specific to that Nation). If that were done, would we not have the tools at hand to create the type of historical engagement that you say (and I'm not arguing) is most historically accurate?
Personally, I'd still prefer to have smaller (platoon/squad-size, even individual in the case of snipers) purchase units kept around to enable some customization in picking your BN's attachments/assets.
Your thoughts?