You just have to get over the fast that you properties will probably not be within early driving distance. 

The comment was something to the effect that the new tax changes would be a benefit to me this year as I could expense all of my improvements in the same year if it was the first year to put the property in a as investment property.

I just moved to TN from Lake Forest, IT IS AWESOME with the Autumn leaves changing seasons!!!

How do I change her mind??? 

Best to get advise from your personal Tax professional Laws change in different States/Counties etc. 

Is there a hard and fast rule based on a percentage?

The market always seems to be changing and may vary from city to city.  

Now I changed property manager.

Don't start stretching your budget or start to downgrade the type of home you want because prices went up too fast. 

Lock in your money now and as rates continue to rise you'll see more and more rentors staying in the rental market longer.But beware because the rising interest rate climate could change quickly and with a correction we could see govt policy in a heartbeat that reduces barriers to borrowing and ownership.