To be ready for if/when Level 1 nodes open up again, do you need to have exactly 600,100 XBY on a single address? Can you have more?
Also, do most people run these nodes at home or do you need to set up a VPS?
To register a node you need to have the exact amount, but once it is registered you can add more coins to that address if you wish (the wallet/coins gets placed in cold storage either way). Nodes only break if the balance goes below 500k coins.
You will be able to run them at home of course, or on a VPS. I know a lot of people in the Slack who are planning on using VPS. Energy consumption should be really quite low as well due to the nature of Proof-of-Signature.