When installing from a liveCD, I don't see an option to save my home folder if I am overwriting a previous installation (which I am). I'm used to a simple checkbox with "preserve /home" from my other distros, and don't know what else to look for here. I can back it up /home/[user] and remake it later, but is there a way to save it?

I never saw an option like that. Which distros have that?
Anyways, it is not that you can backup, it is that you should backup your data. Even if there is such a checkbox the installation can fail so that you loose your data.
Also, if you making a new install, I would just recommend to backup the data and repartition the disk, so that you have a separate partition for /home. This way such a checkbox is not needed on any distro.

Well with Vector linux you do not have that option. If the /home and / are on the same partition then I do not think it is possible to save the /home folder. You would need to back up all the data that you have on an external drive. Use a dvd if there is a large amount of data. If you want you can also zip you data to save space.
Hope this helps.

The option appears in the installers for MEPIS and antiX (whose installer is essentially the MEPIS installer with the necessary words changed). And possibly in Debian, but I haven't installed Debian enough times to remember. (I should mention that they do also offer a separate /home partition.) And I do back up; my point was that if the VL installer does not offer to preserve home folders if they're on the same partition as the system, I know I can restore my home folder from the backup later. Since I have used only Debian-based distros for the last seven or eight years until now, I'm used to installers asking both whether they should leave my home partition alone and where I want to place /home (with the system or on a separate partition). The VL installer only asks whether I want a separate home partition, and then if I say yes, asks where.

If I have had /home on the system partition for any reason, as I have, I think it makes more sense for the installer to at least offer to leave it alone. Why didn't I use a separate /home partition? Well, I did for a while, but I used the same user account for both distros (I don't know whether that was the best thing to do, but I refused to keep track of two user accounts for myself), and never knew what to do about ownership conflicts (which distro's "me" owned the files). I got tired of that, gave up, and went back to keeping my user account on the partition of whichever distro I used more.