On the loans, if you make loans less liquid and less accessible then fewer people will own homes because they can’t leverage into a house the can afford over 30 years but not this year. It likely won’t decrease the cost of housing because people still need housing, and will instead have to rent. There is enough capital on earth that those with capital will want that cash flow. See my point on rent : mortgage cash flow arbitrage. This would not lead to cheaper housing, just less people owning housing vs renting and more housing owned by fewer people - mostly corporations that have vast access to leverage at rates considerably more favorable. That seems like lose lose to me.

Zoning IMO is a red herring. Developers have no interest in driving property prices down with their marginal developments. They will develop in a way that sees prices stable or rise, which is favorable to them as property investors. People betting zoning law repeals will magically result in vast Soviet style SRO arcologies housing everyone affordably will be disappointed that the Victorian single family home torn down and redeveloped as a duplex is developed as a four story duplex with twice as much space, with each duplex roughly the same price as the original single family home. There also won’t be a massive selling of existing property because, well, NIMBYs like where they live. Ultimately we will just have less Victorians that will never be rebuilt and a handful more luxury duplexes.