Years ago we didn't require it and just recommended it to the tenant, but it's so cheap and gives our insurer something/someone to abrogate against should we have to make a claim that we don't allow it to be optional anymore. 

This way, they’ll have a vested interest in maintaining high standards of management.To truly understand property dynamics and support the management team, I recommend spending time on-site.

Then, I would recommend connecting with STR specific realtors in a given market.

I'd recommend you sell the place and put your money in a good mutual fund.

Some carriers require limited water damage coverage depending on the age of the property and age of utilities.I would recommend at least 25% (ideally more) when possible and if you're limited to 10% you should make sure you cannot purchase another policy for a similar price.

Can anyone recommend some companies with a track record like Praxis?

I'd recommend checking out the Midwest market.

BiggerPockets also has a calculator to analyze deals, and I highly recommend you start this as soon as possible, even if you are not ready to buy.

Today, that building generates enough passive income to cover his annual retirement contributions.You mentioned taking the 10% penalty, which I’d only recommend as a last resort.

Thanks in advance for the recommendations / suggestions!