By way of comparison, the same year I bought the lien on the 36 acres parcel of commercial land being discussed here at 16%, I bought a lien on a double wide mobile home affixed to a permanent foundation in some remote Arizona town, and I got that one at 0%.The bulk of the property is not in a flood zone.

Would it be possible to file a mechanic's lien on your own property and would this be a way to discourage potential title thieves?

If the property is not depreciable (IE the allocation of the purchase price to land), then it can escape ordinary treatment, but it also isn't depreciable.https://www.thetaxadviser.com/issues/2011/apr/casestudy-apr2...If you find  a cost seg provider that legitimately carves out 60% of the purchase price of a building to short life property, let me know who it is  My experience is more like 20-30% on average of the building basis from an architect based study unless it is something like a Hotel/Motel or Mobile Home / RV Park.

Or "have a few good go to vendors for handyman, mechanicals etc

We are in the Seattle market, so reality is that demand so significantly outweighs supply that on new construction you aren't really at risk of not selling, its more for at what price per sq ft it will end up selling for.But one mechanism build in is that there is a $100k buffer where he will hold at least $50k of his build fee until after house is sold.

We have been thrilled with the upside potential of self-storage and mobile home parks and we've never looked back.

Largely we aim for mobile home deals, we've ran into complications and obstacles when dealing with some of the agents so prefer to deal directly with the buyer & seller, but creating a relationship prior as you're recommending could alleviate that for sure. 

Easy platform to use on mobile devices and I also like that I can view applications before I ask for background checks.

The cost starts with  1.) plan cost (survey, civil engineer, site plan, architect, structural engineer, mechanical/electrical/plumbing (short for MEP) plans, etc.).

Mobile home loan?