In my opinion, the whole respawning at a different place would be a matter of inconvenience for both the admins and the players, as you may accidentally be spawned somewhere you don't want to be. And for the admins, it may or may not be a pain in the neck to program...I know Java and understand that reprogramming the spawn sequence would be a terrible job to have.
That being said, I think its generally agreed that if a player is being killed right after their PvP protection expires continually, that is spawn camping. That doesn't happen often, and if it does, its reasonable to /modreq it, as it is a violation of the rules.
The bigger issue is basecamping and roadcamping. Roadcamping is difficult because it can be difficult to read nameplates if you are doing so from an archery tower, and you also can never be sure whether that player has armed themself. If a road is being camped, it should be up to the player to seek an alternate route, and not a matter of reportable camping. It is a blanket slaughter, not a targeted assassination.
Basecamping, on the other hand, has to be split into two seperate terms. Camping out in a base to kill the owner is not basecamping. I have been accused of "basecamping" for doing this. Basecamping is camping a base with continous murder of the owner. If that is happening, I believe it is in the rights of the player to /modreq for camping. The argument that if you don't have weapon chests outside your base or you don't have an alternate base then you can't report that is ludicrous. It is simply wrong to say that if you don't have enough PvP assets to counter an attacker, then you deserve to be attacked. Its the same thing as saying that if you get sued in court and you don't have a lawyer, tough luck.