Limiting buys would stymie hostile takeovers. Actually, yeah, that wouldn't be a terrible idea. Anyone who wins big because they were able to "strike while the iron's hot" is likely taking significant advantage of their position, and all of their profits come at the expense of people left holding the bag.

No, they don't have as much leverage as you think they might and trying to regulate like this would cause all kinds of systemic issues that could cause far more economic damage then good. There is already halt protections to prohibit dumping where there is not enough interested buyers to handle a selloff for instance.

This would be about restricting institutional liquidity which is just overall a bad idea for the health of the market and retail investors as a whole.

You want to look to fix something, look at fixing HFTs first. They are cancer that affects every market participant.

This in reference to dumping apple? What fallout did that cause?

I feel like any limits would be useless and big trades are often done in Dark Pools which are the wild west. Intro to Dark Pools - Investopedia