Easy credit was available in many other countries too it was our governments lack of action to control unsustainable house prices and actively encouraging them that compounded this.
Keeping rent prices below mortgage rates is not keeping them low. We have extremely inflated rent prices. I'm not saying that we need the Swedish system where there is little or no profit for investors there is a happy medium.
It was our government's constant interference in the housing market that propped up additional demand where there was none. The solution to a problem created by government is not to give government more power.
Whether prices are high or low is an entirely subjective matter and no person or government should pretend to know what the right price is. The right price is what people are willing to pay without being coerced.
Here is what the price system does. When prices for a product go up it is due to an imbalance in supply and demand. So let's say demand has gone up and supply has stayed the same; then prices will go up. This sends a signal to the market that higher profits are available, and will thus attract more competition who want part of that profit. This increases supply, and unless demand has also increased that will lead to lower prices. What price controls (even a little bit) do is destroy that mechanism, so that even when demand increases supply will not keep up. This is one reason why life in socialist and communist countries was/is utter misery.
There is also no logical correlation between mortgage rates and rental prices that would make any sense to try and fix.
Price controls never work in a diverse and open market.
You say it. Prices are like the road signs of the market. You start messing with road signs in a city, even just a little bit, and you will cause a mess.