SSH over Tor & security risks?

Progress so far:

After brew install tor nmap on my Mac, I am able to do curl requests to the Mempool API on my Umbrel over Tor successfully however ssh connections directly to Umbrel are crapping out. I’m using the following command to try and connect:

ssh -o ProxyCommand= "ncat --proxy-type socks5 --proxy %h %p" umbrel@xxxxx.onion

Which return errors…

Ncat: Error: Connection refused.
ssh_exchange_identification: Connection closed by remote host

QUESTION 1: I have a feeling I need to edit the Umbrel torrc file, but I’m a bit lost what to actually add to this file, specially the IP … Umbrel’s Tor IP is and all of the other hidden services listed in torrc have specific IPs. Does it matter what IP I pick, or is there a specific one for the SSH hidden service?

HiddenServiceDir /var/lib/tor/sshd/
HiddenServicePort 22 10.21.21.??:22

QUESTION 2: What security risks am I exposing my node to, by adding SSH as a hidden service in the torrc config file? Is there a reason why it is not active by default?