I don’t buy the idea that these kinds of restrictions will ever become universally (or even nearly…

I don’t buy the idea that these kinds of restrictions will ever become universally (or even nearly universally) enforced.

Why?

1. Because advertising, like many other forms of capitalism, is a race to the bottom that subverts any attempts to ensure quality. Advertising optimizes for metrics because it is paid based on metrics, and the least-effort means to provide comparable metrics will be used. Bad ads can risk being totally ineffective because it’s a safe bet that the people paying for them won’t realize they’re ineffective until the bad ads have already made enough money to justify the effort.
2. Because the largest ad providers in the world (Google’s Adsense and Doubleclick) already enforce quality standards for ads and already enforce many of the constraints you’ve suggested (to the extent that they can). By doing so, they yield part of their potential market to middle-men who specialize in low-quality scammy ads. As long as we have ads, we’ll have scammy, grey-legal ads, and the attempt by the largest providers to improve general quality has led to a bifurcation in the ad market between up-market ads and explicitly crap ads. Some ad-blockers allow up-market ads (those approved by Adsense) to be shown with some constraints; this just means that the scammy ads get shown exclusively to the less-savvy users who were more likely to click them anyhow.
3. Ads don’t really work particularly well in the best of cases. Having an ad-based economy on the web is, essentially, a bubble. Any ad is inherently an annoyance, so getting rid of the absolute worst ads won’t keep people from using ad blockers. The widespread use of ad blockers will just make it clear to companies formerly using advertising that the utility of advertising (particularly on the web and particularly through media that are clearly ads) is minimal. Already, there are plenty of ways in which the traditional web-based ad ecosystem is being circumvented: patreon and similar crowd-funding mechanisms are supplementing or replacing ad-driven content because ads don’t pay without enormous volume; large companies are sponsoring high-quality content that is largely unrelated to them (GM sponsoring Backchannel & the Cracked Podcast, for instance); Google Contributor uses the existing Adsense infrastructure to directly pay ad hosts with money uploaded by users without involving the advertisers at all; while that standalone bitcoin-mining machine intended to pay for content passively doesn’t have its economics straight yet, a similar system is perfectly feasible in theory; various attempts at automating the music royalty system seem likely to yield or inspire a general-purpose transcopyright-style micropayment infrastructure for derivative works & content reuse. Some or all of these things will eat up enough of the web ad ecosystem to make the changes you propose pointless long before enforcing them becomes practical.