Growing populations typically demand more housing, which can drive up property values and rental rates.

Should I be a private lender since rates are so high?

It is very hard to do an FHA 3 & 4 unit currently because it has to pass the self sufficiency test and with where rates are at it is unlikely to pass.

We did two loans with them and they majorly dropped the ball on both almost costing us the deal.

I have a property manager actually do the showings, but any issues like plumber , electrical is a phone call away.The only challenge is it's a commercial loan, which requires more down, higher rates and shorter terms. 

Properties equipped with the latest technologies and sustainable features often command higher prices and rents, enjoy lower vacancy rates, and have reduced operating costs.

If so you definitely  need one.If you or most all of your competition doesn't have one then it's not necessary but it may help set you apart from the competition if you need to increase your occupancy or nightly rate.

Does anyone know how true this is and if mortgage rates will keep going up? 

The only con is the higher interest rate. 

The issue here is in order to increase rents at reasonable rates to cashflow well you need to not just do cosmetic changes they require you to do extensive plumbing and electrical to be able to increase the rents.