I think would like to renew, but they've occupied the property for some time and the rents in the area have probably increased.

Just offer them what you think it's worth in its as is condition.

I have about 150K to invest with the same amount in reserves (but could be used to increase my position).

A LLC will not provide any better protection at your point in investing and will only increase your operating costs and make it more difficult to get financing going forward.Insurance is the real protection, LLC is more for psychological protection.

If they actually look at a property, they're looking for thing like roof condition.  

How are conditions where you're at?

It will end up saving you both a lot of time and increase efficiency.

I have a duplex that I am currently house hacking, which should cash flow about $400/mo when I move out, but am looking at the possibility of adding another bedroom or bath to one of the units, as well as possibly adding one or two units which could potentially increase the cash flow.

Or you can just buy commercial grade mold killer at Home Depot and DIY.However, no matter if you hire a service or if you do it - the mold will likly come back if you don't correct the condition it got it to flurrish.

You'd likely be able to increase rents for that property with renovations, but the higher quality tenants would be hard to come by.