From what I've heard, that rule is quite rarely enforced. Since some portion of tips is probably going to be in cash, the employer doesn't have a 100% perfect ledger of how much each person made in tips, so they aren't just going to automatically fill that gap unless the employee asks for it and backs up their claims.

There are a few implicit incentives at work that would prevent an employee from pursuing that course of action unless it's happening really regularly. I've heard stories about people trying to go after it and facing "unrelated" retaliation. While such retaliation would be illegal if a causal link were proven, the entire thing is shrouded in so much plausible deniability that I imagine most people would just find it easier to take a few dollars loss than pursue legal action. Another thing preventing such action is that many cash tips often go unreported, so attempting to bring all of the numbers to the floor in a legal setting is not something most servers would want to try anyways.

Anyways, that only guarantees a wage of $7.25/hour. That's a poverty wage, and the thought that employees need to fight their employers just to get that is depressing. States differ, but a pretty large number still use the federal minimum wage. Any employer that can't manage to pay their employees a living wage, much less $7.25/hr, should absolutely go out of business.

The answer to all of this is to remove the nonsensical reduced minimum wage for tipped workers. Some states have done this (WA comes to mind) - they make state minimum wage plus tips. Worth noting that the restaurant industry there is doing just as well as anywhere else, so clearly it's not such a harmful thing to establishments.

Are servers able to monetize via ads if they wish?

Perhaps a personal preference, but I find it a lot more intuitive when clicking the post title opens the link to the content (webpage, image, etc) rather than going to the comments. To follow a post's link, I need to click on the "image", and that feels odd.