We want to begin by house hacking with a duplex in order to eliminate our current rent payment and have more cash to invest. 

Is there an acceptable max percentage to increase rent? 

I was told that on a NNN lease, brokers should take a commission of X% of base rent (price per SF x SF) - not total rent (which includes NNN).

Charge the tenants a higher rent rate and include utilities with their rent.

Components of Rent in a NNN Lease. 

I fill like my due diligence would require the guarantor/co-signer to fill out the application because I now have to vet them to guarantee rent payment. 

We plan to hold our primary residence and rent it out.

FHA streamlined (rehab <= $35k) - is it realistic to add enough value with maximum rehab cost of $35k in this area to add value to property/rents?

The short term rental is more aligned with my long term goals, but it is just skipping ahead by a few years and skipping over the 3 long term rentals I had Initially planned for my portfolio.Do I keep the property and maybe drop the rent under market value, while also coming about of pocket until we find new tenants, or sell and use the equity towards short term? 

Of course your lease agreement and lease amount should reflect that in a way that it incentivizes them to take the deal... don't expect to get a good deal by charging them market/above-market rent if you *really* want the property.