Well, there’s at least one Pace owner here, though not a 500.3.
I have a Level.2, which allows me to comment on some of your questions.
The Level.2 includes rack and fenders, but I found it had too much forward lean. (Fixed that with an adjustable stem) I like that one of the tail/brake lights is integrated into the fender. This wouldn’t be the case on the Pace.
The Level.2 likely has the same torque sensor as the Pace 500.3 and it’s great; very efficient and natural.
If you’re going to commute on it, buy the fenders. If you’re going to buy a rack, buy the Topeak MTX rack instead, then you can use their nice slide-in cargo options: tail bag with or without fold-out panniers, basket, crate, etc. Otherwise, let me know and I’ll sell you my OEM Aventon rack for cheap.
Aventon quality is great, I’d buy it again.