Depending on the size and scope of your real estate investments would dictate what makes most sense as to whether get an umbrella policy or an LLC.  

Business entity - probably LLC - with a well written operating agreement that governs each parties' rights and obligations, management authority, spells out how money is spent and distributed, dictates how decisions are made and what type of consent is necessary for different types of decisions, includes buy-sell provisions in the event of a dispute, death, divorce or disability, etc. etc. etc. if you decide to own it individually as tenants in common, you need a property management and ownership agreement that addresses similar issues outlined above.

When you say in Del Valle - I presume you mean in Travis County. if in fact, it's in Travis County, and assuming there are no current deed restrictions on the property dictating otherwise, you will most likely end up with subdivided lots with a minimum of 2 Acres, based on doing septic systems and wells. 

The type of tenant is dictated by the location as well as the condition and type of home. 

Bedrooms are all small, bathroom off the kitchen and on a busy road so we're attracting young roommates as tenants rather than a family...those factors are dictating our rental amount.  

Whereas best practices would dictate that hiring a tenant is not good business, some people do it anyway.  

How much higher will often be dictated by the level of service you are going to receive from that company on an on-going basis.  

Once everyone agrees on what each partner's share is, that share dictates what everyone gets out of the deal, as Tom explained above.Good luck!

The practice of your market will dictate what is and is not included.

Neighborhood dictates market value of 100k for comparable houses.