You could do General Contracting where you'd need knowledge of all trades or manage a team of one single trade. 

I found out later that my contract could have been better.

If the mobile was not "legally" tied to the ground, you should have two contracts.

I have one long term partnership that we share capital but I still do all the work ( rain maker) he is a cpa so he does do the books and tax return though :)  WE built one subdivision together were he put in 500k and I made him 1.2 mil in 18 months net profit so that was not bad.

Especially since I’m already the one choosing rates/terms. 

To be frank, out of all my syndication and private equity investments, NB/NBPC has been the worst performing in terms of communication and responses.

Keep it short and sweet: thank you for your application, the unit has been leased to an earlier applicant. 

Bridge Loans or Mezzanine FinancingShort-term financing can cover the down payment:✅ Private lenders: High-interest, but great for acquisitions✅ Mezzanine loans: Secondary financing sitting behind a primary loan✅ Cross-collateralization: Leverage equity in your existing motel or rentals4.

Another possibility I looked into is simply leave the current SFH as is since we have long term tenant, but build ADUs on the lot.

I would suggest you also research the zoning code so there is an additional upside long term.