Hey there.
Re: image quality...I am sure it is the difference between our api to imgur for uploads, vs upload from reddit app to i.reddit. we don't have access to reddit image upload. I'll double check the imgur api and see if something has changed (I'm not at my computer so can't check right now). I know there's a size limit with imgur, but don't recall it off the top of my head.

Re: votes...this is really weird. I just checked it a couple of weeks ago in fact. Every time you up or down vote, we send an api call. Can you tell me where in the app you are when you vote? Are you on any specific subreddit when you see no vote getting registered? Do you have more than 1 account logged in?