It is a good practice from the start to keep funds separate.

I have no idea what numbers to look at or even how to get this information as "practice" without unintentionally wasting someone's time.

I saw a rant on FB today against landlords (RE Oregon's rent control) and all I could think of is how many people simply can't or don't want to buy a house.

If you practice sound asset protection such as solid insurance coverage plus series LLCs or using trusts in conjunction with LLCs you're OK on the liability front.

More control, more cashflow (most of the time), crazy appreciation, and more professional (maybe?)

As is Kansas City, Oklahoma City and many others in the Midwest as well as the Southeast are the best for cash flow IMO (just make sure the crime rates aren't out of control and the city isn't shrinking). 

If rentals you still need to know absorption levels for rentals and what amenities the competition offers to arrive at a projected lease rate and how fast it will be to fill up and stabilize.I would want to know for instance that there was no rent control looking at  a project like that and that demand was high for rentals and most places were full.

With lots of practice you will be able to identify a good deal quickly and jump on it when the opportunity presents itself.

I know at least 20 “wholesalers” locally and 99% of their deals are total junk and their business practices are questionable to say the least. 

Cant practice real estate, only refer and receice referral fees.