I am interested mostly in buy and hold and flipping houses. 

In the future, I would like to hold and flip properties and build a portfolio.

I took the initiative to learn as much as I possibly could about the business, particularly small multi family buy and hold.

Have you considered going straight into buy-to-hold rentals?

Please feel free to reach out to me if you have any questions regarding financing or buy and holding (those are my two areas of expertise).Cheers!

I surmise his flooring are getting grinding with grit from shoes and traffic...With asphalt and good matting I have some laminates holding up 5-7 years plus.

You will be sacrificing getting on with your real estate experience and holdings, but would be doing a good thing for aging parents and will have a good asset paid down and ready when you are both ready for other living arrangements.  

Seeking Advice:I'm 39 with 52 units,(50% partner 26 units) ranging from SF to MF (18 being the largest) - all hold properties. 

I'll be up front and tell you I'm a novice looking into the buy and hold game with multifamilly properties (2-4).

the solutions suggested that hold the open sash in place, pinching the AC unit in its place will not work against a thief with the leg strength of a teenager.