Greetings! I actually have a suggestion regarding one thing that I felt was sorely missing in both Baldur's Gate games: NPC and item randomization.
Given that I have played through the game more than 20 times I find it sad that after the third time I could already predict what sort of loot I would find in a given container or on a certain NPC. This is obvious if you watch most of the let's plays available on the net - the player knows the location of a certain item or NPC and thus metagames his strategy by heading in their direction. Another example: interesting NPCs like Tiax and Quayle are usually the least familiar to Baldur's Gate players as they appear at the same, set locations, late in the game. Adding a randomization element to the items and characters makes each playthrough exhilarating, especially when you choose permadeath mode - I can vouch for this since I have been working on a NPC/item randomization mod for BG1 for some years now and have already tasted some of the wonders this game mechanic (a staple of rougelikes) can provide.
The other thing I would like to suggest to the makers of the new Baldur's Gate - if they even read this, that is - is to make sure that they allow the player to drop items, just like in the old games (I haven't played DoS, but I believe this was also the case). This might be a thing that seems irrelevant for the gameplay and probably difficult and time-consuming to implement, but I found it frustrating in, say, Pillars Of Eternity, that you would have to carry all your items around (regardless of their weight and size) or send them off into oblivion.
I'm very pessimistic regarding the new installment in the series, as the bar is set real high and the priorities of game developers have radically changed since two decades go, but, as an ardent fan of the series, if the studio is honestly open to fan suggestions, I'm willing to dedicate my time to contribute.