The parent series LLC has no relationship with any of the cells except being the parent that created its children.

*This post does not create an attorney-client or CPA-client relationship. 

@Brian Van Pelt makes a great point that will that can often be applied to to friends, family, coworkers or anybody you have a meaningful relationship with as relationships can sour just as much or more than a potentially failed investment, which is often enough for a person to avoid helping loved ones when large sums of money are involved.That being said, since you're looking at the risk vs. reward in this scenario, it could be structured in such a way that definitely limits your downside and maximizes your upside. 

We are looking for pointers to local banks (Tarrant County area) that are willing to develop a relationship with higher net worth investors.

Build a trust relationship with a real person who has opinions on more than just insurance. 

Most likely means you are in a transactional relationship or using a CPA that uses an outdated hourly billing model. 

Developing a relationship with a banker will go a long way.

Work with an insurance broker who is licensed in all 50 states and also specializes in working with investors.This will help you both build a relationship with one person and keep your asset portfolio consolidated as it continues to grow.

Is there anything else that I can do to protect our relationship and the contract we signed?

*Goes without saying, but this answer doesn't create an attorney-client relationship.