Here's a pointer for you...
That saying, "If you can't say anything nice, then don't say anything at all" is on the target.
Here's what you do. If you are going to get nasty, rude, ungrateful, disrespectful, etc (any of those mentioned!) then just leave. Come back like a week or a month later.
Some time ago I tried to put in feature requests... Perhaps I wasn't explaining myself correctly.. But I was starting to get frustrated.. Which is better.. (a) cuss everyone out -or- (b) me to leave until *I* calm down.
I chose "b" since that is the SMART thing to do. Surely, if you have any intelligence, you can realize that for yourself too.