I'm having that same issue (#5) that the OP mentioned - basically I have a room mined out, designate it as a bedroom, and then indicate a spot to craft a bed. However, they don't clear all of the mined chunks and never place the bed as a result - they'll eventually get around to it, but it takes way too long.
I've been able to recreate that issue.
I have a bedroom full of rocks Day 8 of Autumn that a Dwarf is actively using.
The Rocks aren't cleared until Day 2 of Summer.
If they get cleared *eventually* then its working as intended, but its not great. I'll be adding a work prioritisation option so you can help influence what they choose to work on next (currently it is whatever is nearest that they're able to do).