Most people in the solar industry recommend going with a new roof and traditional solar panel arrangement.

The only challenge with this property was organizing a cash for keys arrangement with the current tenant to give them extra incentive to move out in a timely manner.

If so, sure, if not go with #2.2) Seems like a great option.3) If you are giving notice to the tenant, then you likely don't need the code, they could meet you there or arrange to leave it off.    

With this rent to buy arrangement, will you be able to evict him?

It always happens that the number of listings gained out pace the number of buys simply because the vast majority of people are going to sell traditionally.If you aren't up to outsourcing or mounting your own campaign, you could always work out an arrangement with local wholesalers who talk to a larger number of people who want to sell, as opposed to "needing" to sell. 

If the wholesaler closes on the deal, then maybe seller financing can be arranged with the end buyer, but I don't see how their assignment fee would be included in the transaction.

I have the floor layout that indicates the seating arrangements in my listing as well as photos that clearly show how things are laid out.  

Also-- you won't know who is coming to your property, when, so arranging say a plumber or HVAC would be a nightmare.

If that's the case, you'll need to decide whether to approach the city right away and see if they will work with the arrangement you already have or if they will force you to tear the drywall and everything out so they can inspect from the beginning ($costly$)If its zone single-family only in an entire neighborhood of single family, then the city zoned it that way for a reason and will be unlikely to approve a spot zoning change for your property.

I have just renewed my mortgage  and because it is almost paid off  I arranged for access to a line of credit.