For example, the tenant didn't replace a single light bulb or the tenant took the batteries out of the smoke alarm...it seemed it kept going off when they were smoking apparently.

Others have already indicated why you shouldn't put your tri-plex in the LLC, so I'm just going to address the words I underlined above.So, your tax guy is smoking crack - a lot of it - and here's why.An S-Corp is meant to be a business. 

Hopefully by that point I've built a strong enough relationship with him that he says "yea Derek I'd like to invest in it with you, your numbers look good and I trust you" In other words unless you have a smoking deal sitting in the coffer you don't want to ask for money, you want to build a relationship. 

I think what you suggested is a great idea  as it would be cheaper for everyone as the attorney would not have to learn about how this person or Company tries to blow smoke. if you decide to go that route please let us know

We tried to go back to the seller and get a credit to do the panels and bring the fire/smoke/CO monitors and alarms up to code, and got shot down.

I have smoke detectors there too .

I’ve marketed “smoke free” reasonably successfully in the past but in my market with so few pet friendly rentals I’m not positive it would work.

Also keep an eye out for evidence of any lease violation.... unauthorized occupants, unauthorized animals, tampered smoke alarms, damages, etc.In addition to checking all of the smoke alarm devices, plumbing fixtures, electrical fixtures, appliances, and operation of doors and windows, ask the tenant if there's anything that's not working or needs attention.

Smoking allowed in household?

So the owner may end up having improper restoration work done, doesn't smoke seal necessary areas properly, then when a renovation company comes in and finishes the work, come next hot summer season, the smell of smoke comes back). - If they look like they might consider selling, you have to start looking for restoration companies that also renovate who guarantee their work so you can figure out the cost.