(I have a background in engineering and experience with rehabs.)It's right at the top of what I can qualify for on a personal mortgage but when I add in other revenue generating opportunities things quickly change.Before my wife and I jump into this I'd like to reach out to the experts. 

I went to school for civil engineering.

(computer engineer here, aka massive nerd 🤓)Looking to Get Out of BPCON2024:- Meeting awesome new people to add to the tribe, and hopefully bringing significant value to at LEAST 10 people I meet this yearGreat Connection, Someone Who's an Expert In:- Business acquisition (M&A)Session:- MINE, because I hope to deliver a ton of value to folks!! 

Engineering , permits , stormwater management system , clearing , reforestation fee , sediment control , and landscape bond , all this would run you around $175K .

An activity is a personal service activity if it involves the performance of personal services in the fields of health (including veterinary services), law, engineering, architecture, accounting, actuarial science, performing arts, consulting, or any other trade or business in which capital isn’t a material income-producing factor.7.

I have had it an unusually long time due to anything that could go wrong did...bad weather, bad GC and back and forth getting the engineer plans through since it is a FEMA zone home.

To make extra sure it appraises high enough for the refinance, this would be after I talk to an inspector and get a few GCs to bid the job, might also get a structural engineer to come up with a repair plan for the GCs to look at when getting me bids.

In Reno, NV the Tesla factory and building of the Tesla Semi-truck factory has been bringing more, construction, executives and engineers to the area for 1-8 weeks. 

I have heard developing an rv park one should budget $30k per space, which seems high to me but, all the 50 amp underground power, waste plumbing, possible lift stations, pads for rv's concrete use areas, pavement, landscaping, engineering, surveys, sitework etc, maybe?

You should engage an architect or surveyor/civil engineer for something like this.