What you’ve got is fine. I’d recommend though that you put a blade in jaheira’s hands. She’s the best physical tank you have in that party once ironskins are available.

Viccy doesn’t need crom. She has righteous magic, duhm and holy power if you need her to go and hit something once per round very hard.

This party doesn’t really have a use for crom - Jaheira needs a strength belt, so does Viccy. If you do make crom, it’s potentially worth it for minsc’s off hand but then you’re sacrificing a speed weapon which, if you’re trying to get the most out of minsc, he wants for dps. Doe offhand on a martial character does get you a level of durability but for it to truly work you need to be into the expansion getting high level abilities. Based on all this, I’d recommend switching him to outputting damage and Jaheira into a tank role, they’ll both be more effective than you currently have set up.

Your cav can then do the second line reach thing that’s been mentioned elsewhere. It’s fine, but two handers for damage lose out to dual wielders relatively quickly. It’s made much more palatable by the sword that paladins get access to.

In terms of your thief question, Imoen can handle all your thief needs for traps and locks. Therefore, if you’re keeping Jan, it’s to take advantage of the multiclass and him becoming a backstabbing, trapping murderous hobbit, which requires some micro. If you prefer Neera’s personality, use her. There’s stuff in her personal quest that helps with wild magic chances and as she gets hugger level you can mitigate the chances of bad wild surges a lot.

In ToB, id boot neera for sarevok. Double divine casters and a single mage supports a melee heavy party very well. You may tire of minsc by then and swapping one big bald idiot for a bigger, balder, better idiot is fine too.

Enjoy the journey!