Furthermore, section (c)(1)(C) implies that removing ANY content by a user could make the forum liable for ALL OTHER content posted by that user, unless there is "good faith", but "good faith" is defined in section (g)(5)(A) to require all moderation criteria to be defined with "particularity".
Most open-ended subjective moderation criteria (such as used on Hacker News e.g. "Be kind. Don't be snarky") could be construed to lack "particularity" and is often about things not on the list in (c)(2)(A).
For example, imagine an employer wrote an employment contract signed by all employees that said something obviously against the law, like "if you get pregnant, we are letting you go". Even though employees signed this contract, that specific clause was against the law, so there is no way to legally enforce it. If the employer tries to legally enforce it, they will be in for a rude awakening.
Another, more realistic, example. Let's say you are about to get married and decide to get a pre-nup. Both you and your partner sign it. Let's say both signed a clause that says "any future earnings made during this marriage will get split 90/10 in case of the divorce, not as a 50/50 split". If divorce actually happens, this clause will be entirely useless, despite both parties willingly signing it. Both of the people who signed it will be able to claim total 50/50 on the split, even if they initially agreed to a different split.
tl;dr: the law overrides anything one can put into their terms of use or any other contract.