Question: Should I collateralize the loan (if using private or hard money), or rely on roll-over loans (to maximize the lower points and 3-4% rate)?

You'll simply sit vacant for a few months, lower the price then get a tenant.

I would look at the DSCR loan as the first option.By the way, I suspect you are going to be disappointed by any refi appraisals   ADUs typically appraise poorly   JADUs can lower the property value Vs having the space as part of the primary unit.  

New Britain is where you are going to get the best ROI like you mentioned and this is because as a whole there are more areas within the city where qualified tenants are looking to live and the purchase prices are lower while still maintaining competitive rents.

Sales Tax Breaks: Construction materials and services may be subject to lower tribal sales taxes—or exempt altogether.4.

You will hear about west side vs east side, while what is told is true, what is not mentioned is lower class areas are block by block. 

Some local banks are fine with 20% down but I don't think they'll go any lower.

Provo ConnectionsUsing your friend’s connections in Provo is smart—it lowers risk.

Often, it will also need work.So, that is causing investors to lower their standards and buy Class C & D rentals.Problem is, most investors apply Class A assumptions to these Class C/D properties - and then blame everyone else when they don't get their "expected" results.Check out copy & paste info below for more dtails:------------------------------------------------------------------------------------------------------Recommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.Property Class will typically dictate the Class of tenant you get, which greatly IMPACTS rental income stability and property maintenance/damage by tenants.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a property in Class D area to Class A standards, what quality of tenant will you get?

Quote from @Devin James: Gross Margin is an important calculation for developers/builders.Gross Margin = Gross Profit / RevenueWe shoot for a 20% gross margin on our New Construction HomesReal #’s:Home Sales Price: $374KClosing Cost: $18,700Cost of Construction: $258KLand Cost: $30KGross Profit = $67K$67K/$374K = 17.9% Gross MarginCame slightly short of our goal of 20%Homes Values and Build Costs are constantly fluctuatingI wish we had a crystal ball build larger homes. average new build in our market is 2200 square feet, 4 beds, 3 baths, 2 car garage and sells for 515k. construction costs lower if design is good and find the median or average home sale price and push that up. my guess is you built too small. 347k is cheap. we target 429-479k price range in columbus ohio for single family homes and also only purchase close to urban core where premiums are 20% higher and we build smaller like 1500 sq ft where price per square foot goes up.