Can you tell the computer that the opponent will call an all in pot size bet with a small flush draw with one to come?

Can you nodelock both the opponent and yourself? For instance, can you say that he never willingly plays a hand with a deuce or three and you never play a hand with a deuce.

Expect both answers are yes but double checking.

Also, if you nodelock the big blind to fold to a raise with the worst 10% of the hands it should call with, how much does he cost himself if he plays the other hands normally? What if the big blind adjusts to the fact that the other guy is sticking to GTO. What if he adjusts to the fact that the other guy is adjusting his play on all streets based on the big blinds extra tightness extra preflop tightness. (The assumption is that when the big blind has the button everything goes back to normal.)

The answers to the first two are both yes.

As for how much the BB loses by folding the bottom 10% of hands he should call, there are a ton of different parameters. What is the rake? What was the open size? What position opened? Were there cold callers? But the answer in general is that the BB is not losing much if anything by folding the bottom 10% of hands he should call. Because a lot of those hands are 0 EV. They don't make money from calling, but don't lose money. However, in theory if these hands are all folded, the BB may be exploited by the original raiser widening their range. Some players figured out a long time ago in early online days that you could open literally an two cards from the button vs a lot of players to 2bb and automatically profit. Nowadays online players are better at knowing what hands they should defend. So the risk of not ever defending the bottom 10% of your defending range from the BB is that the original raiser widens his range so that this range actually becomes profitable for you to defend and not just 0 EV.

If the big blind is adjusting to the fact that the original raiser is playing GTO, then the big blind should play GTO.

Your last question is what should the big blind do if the original raiser is adjusting their range to the big blind being extra tight. That depends. When you say the big blind is extra tight, does that mean they are just folding more of the bottom of their range? Or are they just calling hands thst should be 3betting a decent amount of the time or always? Like AQo, TT, etc? In theory, the original raiser is probably looser preflop to steal the blinds more, so the original raiser probably should be better higher boards less often and they can be less worried on lower boards that should connect more with the BB's range but won't because the BB folded hands like 64s, 87o, that might have been defends in theory. When there are less combinations of nutted hands like 2 pair and sets that BB can have, the original raiser can out a lot of pressure by betting large postflop.

The difference is postflop play would be very dynamic. On higher boards when BB is tighter, BB can probably defend postflop with stronger absolute strength hands because more of their hands connect with the board. On lower boards they probably get to check raise less often and are probably forced to continue more with weaker hands like A high or K high because those hands will be more towards the top of their range on certain low boards.

You can just set the solver to have the ranges you are looking for and see how it adjusts it's strategy. Generally speaking, the looser the big blind is, the more you see the preflop aggressor playing polarized strategies like checking or betting 75% pot or even overbetting the pot on the flop (depending on the board texture). The tighter the big blind is, bet sizes in general go down from the preflop raiser.

BvB it will cost him massive amounts.
BB vs BU it will cost him less because SB will be there to punish BU into opening a close to normal range. In a real scenario SB is very unlikely to punish BU in this way and BU will open much wider to take advantage of BB.
BB readjusting later to account for his previous leak is how a nodelock works as a default.

It might depend on how you take the meaning of "the worst 10% of the hands it should call with."

Looking at GTO Wizard 100bb NL500 rake, BvB, BB folds 42.7% of hands, calls 41.2% of hands,and 3bets 16.1% of hands. Of the hands it calls with, 41.2% of 1,326 combos works out to 546.3 combos, and 10% of that works out to 54.6 hands. That is how I interpret, "the worst 10% of the hands it should call with." As a native English speaker I am pretty sure that is the literally meaning of that phrase. However, I could see how one might think, "the worst 10% of the hands it should call with," as being 10% of 1,326 total combos, or 132.6 combos, the lowest EV combos of the 546.3 combos you are supposed to call with.

But if we are using the former definition, then consider K7o, K6o, 97o, 98o, 87o, 76o, 65o, 54o, 94s, 93s, 62s all mix calling and folding (K7o, k6o, 94s, 93s all mix 3bet as well). They are all 0 EV. Q8o is also 0 EV but it only mixes call and 3bet. If you add up all the times that these combos call, if I did my math right plugging the call % times each combo from GTO Wizard, it is 53.4 combos. Then 98o and 73s are pure calls but only have 0.01bb EV, and that is enough to get us past 54.6 combos with less than two combos having just 0.01bb EV. Under that definition, it seems hard to imagine how this equates to massive amounts.

If we are talking about folding 52.7% of hands instead of just 42.7% of hands, then yes that seems like a big leak.

Seems like the bottom line is that if you are in a game (because most of the players are worse than you) and you are facing a raise from someone better than you it is correct to disobey the solver and fold extra hands, especially if the better player doesn't know you are doing that.

That is a tricky question. You have to ask yourself, why is the player is better than you? I think generally edges that players have on other players are a series of leaks that begin with incorrect ranges preflop. In the long term, the correct answer is probably that you should learn and play the correct ranges preflop and learn how to play better postflop. But sure, in a special game full of whales and one pro that is leagues ahead of you, it is probably okay to just avoid the pro and tighten up a bit vs them

Yes, I would agree with that in principle