I have high hopes that not only will there be an excellent modding toolset, but that there will be an export character option to easily play stand alone adventures/modules.
I'm fairly confident there will be. One thing nobody has mentioned (at least that I've seen so far) and which is often overlooked is that a savegame editor would be really nice: your "export character" reminded me of that but in addition there's often a benefit to adjust stuff or to be able to look things up to assist with modding. I'd be nice to not have to resort to a hex editor or strings and hope for the best (I've had more than one headache using that approach, which has typically not been very fruitful).
I'll go ever further to say what I really would like to see are officially released modules that we can buy and piece together, just like you might with a table top group.
Hmm. From a personal perspective I am not a fan of anything that looks like a microtransaction or other chargeable piecemeal content; I would hazard a guess that Larian might curate some of the more popular user-made mods as has happened with DOS2.
