This is good info! I'll follow up with the provider. Unfortunately even though I live in a large city, of the two dozen or so places I contacted only two of them would consider less than a half rack.

consider server motherboards with KVM over IP capabilities

I had not considered this. My plan was to initially just swap the consumer grade stuff I have over to the 826 since it supports ATX, but now I'll reconsider. Remote KVM has come in handy a few times with my dedicated servers over the years, so lacking that would suck pretty bad. I don't know that I won't have access, but several of the other providers stated on their websites that shared cabinets won't have physical access (which I honestly would prefer since I'll have several thousand dollars in hardware sitting in there).

Data centers are businesses and as a costumer they should be answering your questions about their operating policies. If they aren’t consider a different DC.

Great point and I totally agree! Just didn't want to walk in like a complete noob asking a bunch of dumb questions if I could prevent it.

You’re no longer behind a home router with a firewall that has sensible rules, so it is now up to you to avoid getting pwned and footing the power bill. It is also up to you to avoid spamming out stray traffic.

Thankfully I've got quite a bit of experience hardening servers exposed directly to the internet. *knocks on wood* So far I've managed to not get pwned by turning on automatic security updates, keeping open ports limited to ssh with password/root login disabled and reverse proxying everything. If I need access to something that doesn't need to be exposed I just port forward through ssh.