I just tried a non import game.
I believe the game is a little bit too hard, why?
Well the chapter 5 is ok, it starts getting rough at chapter 6.
Because in the very first "main" mission at arvendel dome, you have to develop a total of 12 characters fairly well for the 3 party split, but here's the problem - there is no great leveling spot that gives good exp/gold, and you have two required characters, which means you have to farm exp in five sessions to get your 12 characters up to a good level for the dome. Very very painful to spend that much time leveling up, but you have to considering you have inferior equipment and gold and levels.
Wayyyyy too many characters to level up, and you don't have seed pendants. You also don't have good access to cash - there are no good fights for gold, and you can't even burgle houses or reduce merchant price because you lack the items from LF1.
Lacking gold/items from nonimport is OK, but I think it's a huge problem for non import that you have to spend so much time leveling up all those characters, especially with random/luci as required ones.