After asking the other editors of TV.com, I have been informed that there is not a maximum number of quotes. Here is what I have been told -
Physically or programming-wise, no.
When discussing submission guidelines, staff has suggested:
2) We want folks to pick the best quotes. Without such a policy, some contributors tend to be rather... generous about quoting everything a star has ever said.
They've also posted about the copyright issues here:
Here's a good guideline: a single quote will almost never get you into trouble. The more quotes you submit from a single source, the more likely TV.com has to reject because of copyright issues. There is unfortunately no exact number that we can say "This is safe."
Like many things, what that limit is ultimately seems to be editor discretion. As an editor, someone is more likely to get in trouble if they start breaking their own limits. Like rejecting a quote by saying "There's a limit" and then putting it in themselves, either replacing an existing quote or deleting another one. In that case, they should still reject, but tell you what quote to replace and let you do it.
Also, an editor should make it clear (probably on their Blog page, but in the person forum as well), what the limit is. Obviously, if you get a rejection and the editor says that you hit their (unstated) limit, but a day or two later a new quote shows up and there's one more total quote than there was before, the editor isn't applying that limit consistently and fairly.
This is the line I will be following when a quote is submitted, and ask that everyone reads and trys to follow it as well. Thankyou.