klik on older knoppix versions

[probono]

1) Other than the packages needed by the klikable app, are all the required package versions (that knoppix needs to run klik) on v3.4 ?

Yes.

2) If all the packages (that a certain klik package needs) are updated to the same version as v3.7, then klik should work fine, right?

Correct.

3) if a package version is older than what's on 3.7, does the klik install break, or will klik detect it and try to upgrade the outdated package?

No, because klik doesn't check what you have installed in your base system. It blindly assumes a set of packages that is stored on the server. klik tries to detect which distribution you are running and if your distribution is known to the klik server, then the server knows the correct list of packages it assumes to be present. If klik doesn't recognize your distribution, it assumes that the "least common denominator" of packages from the supported distributions is present in your base system.

Hope this helps.
Greetings,
probono