If the listing agreement has a lease provision then the seller will instead pay the lease commission when you take possession.

If they want to but specify that even if they don't, landlord isn't responsible for lost possessions. 11.

If you default once, does he regain possession of the house and you lose the 10+ years that you have paid him the $2,000 a month?

I want to sign the lease and take the sec dep. first and last months rent....but I am not sure if that is customary to do given the gap in time before the tenant takes possession of the property.

I do however don't know if they will try to claim possession since they made upgrades to the property. 

If you are referring to adverse possession laws, that will not work because that is not how the law is written in Texas.

I’ve had the deed (eg not just the tax lien) and possession for over 3 years and was denied title insurance when trying to sell it because I haven’t filed a quiet title yet.

Since I have taken possession I put in all new carpets and it is now occupied by tenants and is cash flowing $650/month. 

When you win a foreclosure auction, you get possession of the property. 

I have a seller but it has a reverse mortgage and the seller wants me to pay the reverse mortgage and take possession of the property.