If you want them out I would make it a condition of the sale.  

Includes Upgrades such as New roof and hardwood floors (2016), 2019: Upgraded plumbing, reglazed all bathrooms, new bathroom floors, new vanities , new fixtures, new toilets, all new appliances, multiple zone heating and air conditioning mini splits, new water heater. 2021: upgraded electrical panels, added basement heater to prevent pipe freezing in winter...

We were shocked they were asking so much for the property in this condition, however, it did include an additional 0.7 acre parking lot which included 100 spaces.I gather with my client and write up the offer.

I'd make the seller pay for by factoring it the original purchase price (along with other repairs to bring the property market condition).

Does the price comp out based on age and condition?

PenFed will do one with the conditions you mention, and they don't do them if you have over 4 properties mortgages.

If they are a good tenant otherwise, maybe offer that you will get the lawn back to a manageable condition via lawn care service, then he can continue to maintain it for the $50/mo discount, or if he doesn't want to do it, he can just pay the normal lease amount.

If the home is in good rentable condition you shouldn't have much of any issues. 

What made my investor interested in this deal was the location, condition, and the good rent as is.

Regarding the walkthrough you should have something that documents the condition of the property when they occupied the unit.