I'd avoid having your husband co-sign if you are looking to build a large real estate portfolio.

Low time commitment: The sponsor handles all the day-to-day work.Lower risk: Investors can leverage the sponsor's experience to avoid costly mistakes.Economy of Scale: Sponsors tend to buy larger properties.

1. cashiers check money order or zelle(once a zelle is sent it can not be cancelled), avoid credit cards because they different laws regarding consumer protection that allow for chargebacks....avoid cash, you don't want to be known for having thousands of dollars on you2.

Many criminals avoid places if they know there is a chance of getting caught.

I need to establish clear rules to avoid conflicts and arguments for my own peace of mind. 

I'm trying to avoid analysis paralysis here - but it just comes so damn naturally to me...

REI has the benefit of Leverage (no margin calls, as long as you lock in your Debt) and Tax Avoidance.

And as @Ashish Acharya mentioned, it's always best to be conservative and avoid greed.  

I'm learning a lot and the city has also had some cool recommendations (how to deal with heating and the concrete slab with sleepers, recommendation to get pre-engineered trusses which avoids increased structural review). 

We know it could unlock our ability to buy a lot more properties, a lot sooner, and with greater ease, because we could completely avoid the limitations and lending criteria of banks.But we also tend to believe that Seller Financing is rare and hard to find (especially in a competitive Seller’s market), or that it’s difficult to negotiate even if you can find it.That may just be a limiting belief, however.