I've not looked at what I could get for rent ahead of time, like you have, but it's a large apartment with 1 bedroom, 2 other rooms (office plus bonus room, etc) plus a brand new open concept kitchen, with its own separate entrance and garage access. 

When I click on his site, the payment info says "page not found" .

Not all properties will cash flow (either initially or some ever), but at the end of the day when you sell them, you should come out ahead. 

I went ahead and made the repairs.

It sounds like you're ahead of the game here because you're focusing on your local market, which certainly makes things much easier. 

It's $350, but if your policy is more than $4k (or higher like mine), you'll come out ahead.

That's good, if the water isn't running you can go ahead and start doing the work but I would thoroughly document the damage to go after the owner with, at least threaten with a demand letter. 

Click on the name of the person that you want notified via an email, that you responded to them.

Depending upon the local laws, it may be possible that any similar property could be a STR just by a few clicks of buttons to post it online.  

With that being said if you're using an esig software we are talking about a few clicks why not just do it the long way to be safe.