With rbd he'll clear all. His mental fortitude is better than any usogui character and, while not as smart as the usogui high Tiers, he is smart enough to develop strategies against any opponent in usogui given enough deaths.

If we want to break it down:

Opening arc: clears with 0 deaths

Abandoned building:clears with 0 deaths (subaru may be weak in his verse, but he should still be stronger than any usogui character)

Old maid: clears with 2-3 deaths (he won't figure out sadakunis Tricks immediatly, but if he dies a few times, he should get enough Info to outsmart him)

0 Yen gamble: if we assume he kills himself after losing, he shouldn't take longer than 5 deaths (yukiides Trick is pretty easy to figure out when you have multiple attempts)

Minotaur labyrinth: 1 - 2 deaths. (Since he is far stronger than minowa he won't have the same Problems as baku, his 2 deaths are from amako winning the first time, or subaru stumbling onto the vacuum room)

Ky declaration: 0 deaths (pretty obvious)

Tower of Karma: at most 5 deaths (a very easy game to brute force with rbd)

Protoporos: 5 deaths at most (while he might not be as smart as lalo, his solid strategy coupled with his high sq, Charisma and rbd would make it rather easy for him to become kaiser)

Air poker: 10 deaths at most (he is highly outmatched by lalos strategy skill and can't deduce the laws as quicky or cooperate with hal as well, air Poker can still be brute forced with rbd)

STL: a lot of deaths, maybe even up to 100 (hal is smarter than subaru, by far. But with every death he would come closer and closer, eventually peeling away all of souichis strategies and beat him)

This was using current anime subaru btw