It pushed more debt onto the financed property, but lowered our interest rate by a lot on the new loan, plus freed up another loan slot to buy more properties down the line.  

If you get their cameras installed just make certain the installer caulks the top of the cameras (where the memory card is inserted - the memory card is optional but there's a slot for them on the cameras I have) to keep any water from getting in, because it does happen. 

Quote from @Daniel Apke: Nothing pisses me off more than poor quality listings.

One of which is trainers utilizing my space and pay me rent for time slots to teach classes.

That said, you will need to refinance off FHA to clear your 1 FHA slot to then do the new purchase with FHA again. 

IMHO it's more important to take action on the "how's" than spend too much time tracking 5 different metrics or spending too much time analyzing goals or creating even more that likely won't get done.Another great tip-- put EVERYTHING on your calendar so you have specific time slots for all the "how's" you need to get done and stick to them.

No more investors can step in at that point on the other units if they want to use a loan to purchase.Maybe I'm worrying too much about it since, if I own a unit as an investor, and I want to sell to another investor, they can still purchase it because they can just take my "slot" as one of the investor units.How much does that situation dissuade investors, if at all?

If it's not police sirens, it's helicopters, or neighbors dogs, or kids, or planes, or slot machines lol.

You can always refinance your investment properties later to "free up" slots if that becomes an issue for you.Once you moved out of your primary, it became an investment. 

Once you fill the slot you deactivate the listing, your profile stays on Zillow for the next time you need to activate the listingIf needed you can also collect rents through Zillow.