Memory
I was concerned about memory from the beginning and I feel my concerns were warranted. The problem with Memory isn't that your characters are too weak, it's that you are forced to make less fun choices. Divinity is more fun, but not unbalanced, when you can cast a crazy variety of spells. Even if you dump into memory, as I did, you eventually reach the point where you have multi-slot spells. This will force out the utility spells that have a low power level, but make you feel clever when you use them. Memory encourages players to Min/Max.
This, so much this. The memory requirements are way too rigid and powerful compared to the rest of the mechanics.
Divinity is indeed more fun if you can cast a crazy variety of spells.
Journal
When I get a new journal entry, I can't tell what it is. I'm often staring at my journal trying to remember what's new.
Yepp. And actually the journal isn't very helpful at all. It's usually so short that it doesn't contain any valuable information. In an old-school hardcore RPG without (one can still hope...) quest markers the journal should actually be informative, giving the player a clue what to do next, whom to possibly talk to, where to head. I'm pretty sure, a one-liner isn't really suited to fulfil that task in most situations. Right now you have to switch between the journal and the dialogue screen to get a clue how to progress in quests. That's tiresome and would be unnecessary if the journal would contain all the required information you could gather from dialogues, exploration and such.
Quests/Dialog per party member
While quests and dialog per party member might make sense for the model of the game, in practice it meant I often had to run through the same dialog tree 2, 3 or 4 times if a different party member clicked on the same NPC. Sometimes one party member will complete a quest, and another party member will start it again.
Fully agreed.