Personally I’d do a 1031 to save $40k, I’d skip the LLC, increase the limit on my umbrella, and call it a day.

That is a great place to start, as well as hitting some local real estate investor meetups so you can meet some other house hackers in person who have done what you want to do.

What have been the best ways for you to grow your business while still having that personal touch?

Your value is, to provide sellers that don't want to list, with a way to get cash for their house and provide buyers with discounted off-market properties they can buy to make a profit on.I am not saying it is not possible to wholesale from the MLS, but it seriously defeats the purpose.Focus on becoming the person/company that offers the most and best value and you will succeed.

This gives them significant control and security.Joint Venture Agreement with Personal Guarantee: We establish a Joint Venture (JV) agreement that includes a personal guarantee, providing an additional layer of security for our investors.Memorandum Filing: We file a memorandum in the county where the property is located.

This is anecdotal, but I come across of ton of GCs looking for spec-build financing in local meetups and networking groups, such as on facebook on in person meetups. 

Each person would pay $600 a month or even consider padsplit.

I'm happy to meet in person. 

The financing arrangement must be at arms-length and cannot involve a disqualified person (e.g., you, your spouse, family members, or certain business entities tied to you).

And personally, I stay away from OH because it's what herd think has long been and I worry how much of price is based on herd-actions or market metrics.