.)$10K out of my $30K line is only about 34% utilization maximum after I take each chunk.

Tenants may not occupy residence without utility service except during brief interruptions beyond your control.

In that case you should get an attorney involved as encroachment would be a material issue that if known should have been disclosed both to the broker and to any potential buyer.  

Renegotiating some utility contracts (garbage and removing some on site office paid internet/phone bills) 5.

Now I've got a property under contract:$78K purchase$35K in development of utilities.$24K in soft costs (permits impact fees etc)$200K (or less) buildout of the house (size tbd on after-build-appraisal) Likely going with 2/2 A frame 1000 sf.

The best thing to do here is utilize what's called a DSCR loan.

It's uncertain what will happen with deportations but it is certain that the border will be materially closed down. 

If you see utilities increasing, is there a way that you can push this on to the tenant?

Educate the land owner on the potential profit run the numbers and go over the basic proxy and blue prints.Make sure you have a seasoned and qualified Builder/GC because they can be a deal killer with wasted time and inflated material and extended completion dates.

I borrowed $110K from a private lender for the purchase and self funded the repair of the offices. 3 months later, I rented 6,000 sq.ft. of office space to a corporation for $21,000/month + utilities for 5 years with another 5 year option.