I think the reason why "invest close when you start" is the rule of thumb is because it is easier for you to adapt to the unexpected, especially as you are learning. 

It was still a great deal, but in hindsight, I would've asked the seller for an additional $5k+ at closing for the unexpected damages. 

You need reserves to make your mortgage payment and cover unexpected expenses.I will give simple example.  

Batteries doing that average $1 to $1.50/day in credit on an average system.Also - and I'm sure this is not your case - but because of poor education by solar companies, a surprising number of homeowners believe they have "free power" because they have gone solar and use way more than they were before and then get an unexpected "true up".

You shouldn’t even care why it’s not paid (i.e. they broke up, had an unexpected car repair bill, check got lost in the mail, etc).

An unexpected budget expense? 

They can provide a more accurate assessment and potential repair costs.When dealing with homes from the early 1900s, it's prudent to overestimate your renovation budget to account for unexpected issues.

The pilot and the castaway talk about every component of flying, about operating the plane, about landing, about dealing with the unexpected.

OVERALL QUESTIONSI’m wondering if there are any “gotchas” I should look out for in managing or renting either of these properties, especially regarding taxes, maintenance, or any other unexpected costs.

Pit bulls (like any other dog) will protect its pack (family) when it feels there is a threat, however, proper training will keep them from unexpectedly turning on someone...no matter what the media would have us believe.