Ah sorry, just read back through and it seems I missed some details, It's
currently being hosted by a shared hosting service, presumably running some
form of linux, I wouldn't have a clue if its got access to ZFS.

Unfortunately the hosting service has fairly well locked things down and
tried to made it "friendly" to the average minecraft admin as opposed to
friendly to people that actually want access to a ssh console, so may have
to pull a support ticket just to get a way of running the script(outside
running a jar file that I could compile to run the script).

Or change host....

Additionally on a slightly different note, I need to connect to a webhost
from the minecraft host, via mysql, on a port other then 3306 without
disrupting the current mysql set up too badly, currently I have CPanel
access but feel confident that if I talked to the admin I could get SSH or
whatever is needed (same admin is currently paying for the minecraft host,
but the hosting is done for a third party).

With the versioning I need something relatively simple, as I
don't particularly want to be scrounging around looking for documentation
should I ever need to restore a backup...

bup was looking promising until I read:
1. bup currently has no features that prune away *old* backups
2. This is a very early version. Therefore it will most probably not work
for you, but we don't know why. It is also missing some probably-critical
features.

looked at rdiff and rsnapshot and other things but still feel out of my
depth.