I know my parents would have separate accounts for properties depending on ownership structure and property location.

So in the next few years home ownership levels will increase again.

Put the ownership of the property into said LLC.

@Mike D'Arrigo approaching two years ownership.

What we came up with and what I am looking for feedback on is whether this sounds like a good deal and anything I need to consider that I may not have.He wants to start an LLC with me 50/50 ownership.

yes you can. you may need to provide evidence of your ownership and your constriction plans and engineers drawings showing your intent for site. they won't just move it wo good reason. even then get ready to wait.  

Tenants are usually not happy to have a change of ownership in the middle of their tenancy, do your best to put them at ease by confirming that you will honor their lease and what the terms are, and make sure they know how to pay you and contact you about repairs or other issues. 

So if the Grantor owns the property 100%, then they are passing total ownership to the Grantee.

- What other types of proof do you use with 3rd parties for ownership verification purposes?

You will not be held responsible for a bill that was created prior to you taking ownership of he property.