Determining whether my VPS needs any upgrades (generally)

Support
11

I would spin up a new VM and move to it as described at Move a Discourse site to another VPS with rsync. If you don’t mind a bunch of downtime and the possibility that it’ll wreck you system, you can try to do multiple dist-upgrades. If you do that, you should make a snapshot (which also incurs downtime) so that you can restore to it.