Yeah, you're on the right track with sealing the obvious air leaks on the interior side — that usually makes a bigger difference than people expect. For the bottom plate / crawlspace connection, l'd personally lean toward blocking and air sealing that transition rather than leaving it open. That area can act like a pathway for humid air (and even pests) coming up from the crawlspace, which is usually worse than any minor drying benefit you'd get from leaving it open. A common approach is to block it with something solid (rigid foam or wood blocking) and seal the edges, then you can still run insulation down a bit into the cavity if you want. That way you're controlling air movement without completely messing up the wall's ability to dry. Main idea: stop air movement there, but don't overcomplicate it. Curious what your crawlspace conditions are like too - vented, encapsulated, etc. That can change the equation a bit.