There should be no issue if your seller is doing business properly.

I want to continue in the rental business but I want to expand and start doing flips as they become available in my area.

Proper terms are often replaced by lingo

To hit that goal, I've had to expand my REI techniques; for example, I'm going to be starting my first flip on Monday.

If this is the case, could someone tell me the proper & legal way to do this?

I'm a full time civil engineer and I bought my first rental property in 2012, and have expanded to 7 rental units today which net me about $1200/month (self managed).

Which changes the numbers, the predicament of the property, who owns in properly and who is allowed to sell it.

Its a high density area where people can't/don't want to expand out very much so demand is high.

So you need to understand what your BUYERS want and what they plan to do with the property so you can properly market properties to them.I would highly suggest that you understand more about all areas.

I finally learned how to properly evict them and decided now I can put in good tenants that have been screened.What I found out is that good tenants don't want to rent there.