You want to be right at or slightly below the market.Second is to be comparable to the competition.  

I am exploring rural locations but not sure about vacancy and rent rate compare to more active but competitive areas around Houston.

Glocks are really nice, but the are a little heavy for conceal carry,  just remember the best handgun is the one you will be actually carrying, if it is too heavy that you leave it at home, then it won't help when you need it.  

I work as a heavy equipment operator for a sewer and water main company in downtown Toronto, but I have the ambition to do more than just work for someone else every day. 

You will find that will a very well reseached and well managed fund, you can achieve consistent and reliable double digit returns, which is going to be very competitive if not exceed your return on SF investments in most situations.  

Even savvy private lender will probably reject a residence, thanks to the heavy regulation of such loans.

And of course with our competition here for dirt it would only happen if it never hit the open market

I have sold many condos and have only had clients have issues with making interior changes if the change would negatively impact a neighbor, cause noise at inconvenient times or in the Pearl where there are can be a lot of restrictions on interior changes as they can cause structural issues (for example some buildings don't allow you to hang heavy items with maully bolts because of building envelope issues).  

Depending on the competition in your market, the old ARV x 70% - Repairs formula may not win any deals.  

There's a lot of competition from larger complexes offering a free month of rent that compete directly with you for tenants.