I live in LA where in lower games, under 5/10, new players are capped at playing short stack. 2/3 games are capped at $100. I rarely play these because they're a bit ridiculous and the rake is $6. There's one exception, where $300 is permitted, but the rake is $7 should there be a river. I've started trying a 3/5 game that also has a $7 river rake and forces a $300 max buy in. However, I can add up to $450 should I drop below $150. To feel good about my BR, I'd rather stay at the $300 BI. In general, the 2/3 game is full of limpers and calling stations. The 3/5 will usually have 2 to 4 more active LAG players at any given moment, or conversely the tables might be tight with many chopped PF pots from folds. Would it make more sense to play the 100BI 2/3 game considering the rake, or short stack with 60BB at the 3/5 like all other new players? If so, what adjustments should I make to my pf play as a shorty?

I'd go with the 2/3 100BB cap game, all other things being equal.

Though a 60BB game with multiple LAGs sounds like printing money to me.

I'd go with the 100BB, but it's close.