As an LP, how should I compare the track record of a sponsor that began with experience in the market prior to the Great Recession and weathered the storm vs a sponsor that spawned post 2012? 

You wrote:The former owner of this property advised me to not let tenants park in the driveway because they might break the concreteIf this is literally the advice of the prior owner and your rationale, it appears the prior owner is saying you shouldn't allow anything to be parked in the driveway for fear of breaking the concrete. 

I don't want there to be important things that I wished I had asked prior to joining them.

Probably best practice is to try to gather more information about the specific property and owner's situation prior to reaching out with an offer. 

The prior owners had a cat. 

She tells me that she was injustly placed in county jail prior to taking residence and that was the reason that the dog is dirty, full of burrs and fleas. 

You'll have an opportunity to review the condo docs prior to purchase.

@Daniel B.There will definitely be some taxes that you will pay as a result of the sale - the question is how much.You have some 'non-qualified' use when it comes to the 2/5 section 121 exclusion since you lived in the unit prior to having it as a personal residence.You may want to consider doing a 1031 exchange depending on what the tax hit will be.

Do they require your approval prior to repairs etc?

They could demand a replacement of the sewer line prior to approving the ADU application which means there may not be a choice of not doing it anyway.