Future residents could essentially buy out their units and fund your build. 

You're essentially buying into a partnership with your friend with the partnership owning and operating the property.Now, the financial side of that gets more complicated and would generally include an advanced proforma/financial model that includes a GP/LP equity waterfall schedule that is based on how you and your friend agree that you will pay her and also share the profits.I assume that won't make sense to you right now, but I'll send you a DM.

List it on AirBNB and VRBO and use the built in tools.

So there are so many software tools that it would be best you do a quick search.

Grishma GovaniList of best real estate marketing tools from RE/MAX R4 convention

The 1% rule is essentially not going to happen in most markets, unless you are in the midwest or more rural/LCOL areas. 

Essentially I would become the landlord and they will be tenents.

Gaining an understanding of the Zoning is vital to what can be built and essentially dictate how profitable the land can be.

My rationale: - Office is essentially not trading right now on the market.

@Jesse Conrad Feel free to DM your email and I'll send you a copy - which also goes for any others interested in the tool.