The comment limit works as long as you don't have any 'huge' graphics. If you have graphics larger than the limit you set (say, 500px)--or if you put 2 or more graphics on the same line & that adds up to more than that limit--then that will override that limit. Yes, the comments will still be limited to that, but other places on your page will be larger.
Another thing to remember: if you 'see' codes/words on your page where you 'plan' only graphics, that means you copied the code wrong. Even one wrong character will mess it up. I've found I tend to put the one 'caret' in backwards at times, lol (put right bracket in spot where it should be left bracket, etc). If you see the word 'center'...that means you probably either left out a bracket or put the wrong one in. I change my page frequently & still do that at times!
Hope this info helps.