Dwelling coverage is usually determined by the insurance company and is typically based on square feet.

In addition, if the town home has a master policy for the outside of the property should I make the coverage A  dwelling the same as the purchase price or 75k since I am responsible for only the interior of the property. 

If so, purchase a personal umbrella policy to increase the amount of Liability coverage.

You should also make sure the Liability coverage is at the max the company allows on the policy (Typically $500,000 or $1,000,000) and have them quote you an umbrella policy as well.

We aren't talking massive, full-size macro-tower; just the smaller node-like tower for pairing coverage together. 

I would skip charging the monthly increase to the rent as that effectively changes the lease altogether and could be seen as a demand for a rent increase.Require and obtain all pets vaccination records and licenses as well as the name and phone number of the vet.Require Renter's Insurance with Landlord as Additionally Insured coverage - that covers pets so that if anyone is bitten or damage is sustained, you are held harmless and the tenant's policy kicks in for those damages.As long as you change nothing more than the conditions regarding the pets, it's pretty basic.  

In addition to carrying a $300K liability coverage on all of them, I have a $1M personal umbrella policy.  

This can work if you have never asked and have been with them for some time.2)  Make sure you are only paying for coverage you would claim against.3)  Quote out your account. 

I'd advise also having a conversation with good insurance brokers that specialize in multi-units...so you get the right liability coverage there and perhaps supplement with an umbrella policy.

Again, in Texas, Title insurance would only check for ownership, you would need to have purchased additional boundary coverage if there is a dispute.