Can I use closed cell foam directly on the decking and joists?

Spending a little extra time/thought on building a targeted list is going to get you better results, and allow you to spend less money on marketing to leads with a poor chance at conversion.

Than you can use the extra money for a down payment on another property. 

Depending on your state of residence, you may want to form an LLC in your own state; in some cases LLCs formed in Nevada or Alaska may be beneficial, but also result in extra filings.The answer to your question will depend substantially on the following1.

I had only seen the unit over cell phone. 

The deal closed and worked out with some extra closing credits, and the appraisal also came in lower which helped get that price down to better reflect the property. 

I go the extra mile and only require a 5-day notice to vacate and also prorate rent back for unused portions of rent if they need to leave in the middle of the month.

I've got pre approved for a loan and have extra cash saved up.

In a few cases when we needed a particular property to complete a land assembly as part of a larger scale redevelopment, we took the extra step of quieting title in order to protect against the possibility of any right of redemption.

When you add an extra female to the mix, more space is a necessity!