so I found those two arrow-activated switches in the Sleeper's Temple, in the room with elements puzzle near Gor Boba; they click when shot, but don't seem to be doing anything... does anyone have a clue what these are for?

the walkthroughs I have read don't even mention them

Do you have a texture mod installed?

I know there are a couple of switches in the temple that get deactivated by the texture mod everyone uses. Last time I played Gothic 1 I had to un-install the texture mod, activate the switches, then re-install.

Really strange, but it worked out okay.

But, do they do anything? I don't remember them (then again, been a long time).

I think I do, I am not entirely sure :) I tried to install it but I can't see much difference ingame... all other switches I encountered worked fine though (that is two in the nearby death trap room and one in a room with one of the shaman brothers)

I just remember I got to a point where I couldn't progress any further. I had to uninstall the texture patch, trigger the switches, then reinstall the patch and continue.

Whether or not the switches you're talking about are the same ones I'm talking about, I can't be completely sure of. I don't remember any switches in the temple that do nothing, though.