This post is the first time leadership is hearing about your concerns.

LTV can reach 70~80% even the cap rate is only 4.0%.

Renovate and Sell: Given that the house could be worth $500k or more with updates, they could do a renovation first, potentially adding $150k+ in value.

I agree, it could be possible but I have yet to see a deal that really works when the borrower is borrowing 100% financing on a deal as the lender is going to have much higher rates and default rates.

I'm sure you will need tools to find deals (eg price/sqft etc), estimate rents, calculate cash-on-cash returns, cap rate etc.

You sell after 12 months and take no depreciation expense in the first year.  

I also see you're newer to the BP community and this is your first post.

The short version is that you want a strong and diverse job market, low unemployment rates, a growing population, low vacancy rates and new development, affordability/cost of living, real estate laws and court system, good schools, and low crime.Check out the videos from Dave Meyers with BiggerPockets.

Or will rates continue to stay high?

million in addition to their investors (who expect a reasonable rate of return) by keeping the rental rates at a fraction of the market rate?