Nothing in that list was "negative". They were all dry factual statements. Tone policing people for being "negative" when they're not is in and of itself quite a negative thing.
If you don't want to be considered a jerk, in polite company you would say something like "This is a nice project. I have a few suggestions and bugs regarding accessibility:"
"leaves a lot to be desired"
If you don't want to be considered a jerk, in polite company you would say something like "This is a nice project. I have a few suggestions and bugs regarding accessibility:"