...
As for PVP: How about making mars a FFA ?
AND:
[QCraft]...inventory moving can be disabled ... load balancing reasons. For a load balanced world inventory keeping would be allowed. Portals will of course be an admin only tool.
Nether portals are not allowed in Mystcraft dimensions anyway. You cannot light one, and the only way to get one is to cheat a portal block (since it would be a super easy way around getting lost ala Myst/Sliders). I don't know anything for sure about IC2/GT teleporters; seems like I read something based on the presumption a teleporter could send things between dimensions.
Q-Craft inter-server does allow togglable and presumably unbeatable restrictions on whole inventory transport (it's not a tesseractable dimension... it's a whole different minecraftforge jar instance). I don't know if it would be possible to restrictively allow only certain items to move through. Another mod (endernet, I believe) does allow item transport between servers with pipes and such (but I don't know in what ways items can be whitelisted or blacklisted). Q-Craft doesn't have to affect anything on the server except to enable such a portal, really, if you were to disable its oregen. ---I don't know what would happen if you tried to log onto both servers simultaneously, or if there is a way to make the logins mutually exclusive.
As to Mars PvP: What happens in another planetary system, stays in another planetary system. Also... if two consenting adults participate in something and can be adults when someone comes off worse, I don't see why an admin would stop it in any dimension.
While I set all sorts of silly rules for myself, I do agree with BA's statement that a server economy will always operate in the most economical way, and artificial, morally-motivated bubbles will always be fragile especially if there are anarchists afoot.
I still propose a mid-term tick-lag-test with Thaumcraft alongside the rest of the basic mods proposed. It may not even be viable at all, rendering this whole debate moot.