An investor who accepted to help me get started, asked me to put up the money for the repair on a property that is already purchased (I am not on the deed or title) for a return of 50% of the money I put in (after the property is repaired and sold) and When I asked, what's my security on the money I pay, I was told that we will be signing an affidavit of interest in real property.

We are looking for a cloud based (hard wired) security system for a mid-sized apartment building.

Our initial financing fell through and we had to scramble to secure backup financing.

One can easily borrow a million bucks against their securities for around 3 pts.

I did not offer any compensating factors like a cosigner or double the security deposit. 

Technology allows us to exchange documents securely online.Browse this forum, and you will see about 20 tax accountants sharing knowledge here.

Is this a secure strategy for decreasing vacancies?

It also helps should you want to secure financing from that bank in the future.  3. 

It has worked out extremely well with unbelievable returns in the 30-40% return rates not including the equity appreciation of now having secure long term tenants paying huge lease rates.

Is it legal to put a tenant's (or multiple tenants') security deposit into a savings account and then collect the interest that the deposit makes for you?