Mainly the multiclass archetypes kinda suck. If I start as a rogue, I have zero options for monk stuff. Not even lethal unarmed strikes. If I start as a monk, I miss out on much of what makes a monk neat (ki abilities and a large enough ki pool to use them), and don't ever get the stuff that makes a rogue neat (dex to damage, skills, etc). The original character is way more rogue than monk, but if I'm a rogue I can't ever be a monk too.
As I understand it, when I play part 4, I'm to level up the character I played in part 1. What if I had a bad experience playing that character and want to play something else? For playtesting purposes am I stuck?
For my personal situation, I was lacking for ideas and so just attempted to build one of my existing characters and now realize it is just impossible to actually level him up to be the same character character (who is a multiclass monk/rogue).