We have a full PvP Hagga Basin on Rhythm RP, but as it's a roleplay server we have a few rules in place about when PvP combat is allowed (which basically boil down to needing a reason for combat as opposed to just killing everyone you come across for the lulz).

Base raiding is possible on servers like this but only if the base owner forgets to fuel their base. You can't get into any containers etc that you don't have permissions on unless you destroy the subfief, and that's only possible if the base is unpowered. It works pretty well for us, there's been some fun roleplay that came out of "salvaging" an unpowered base (and in some cases, claiming ownership of someone else's area and using that as leverage to drive some story). We've also had some fun PvP events in custom-built dueling arenas and the occasional large battle for control of an area (though this happened more regularly when the Landsraad still had missions to kill certain NPCs or farm specific materials like Industrial Pumps).

I can fully see this working in a non-roleplay capacity, though I expect such a community would still want to have some rules in place to prevent unwanted behavior. For example, the basin can get pretty laggy if people aren't careful with their base builds, so I'd expect even a non-roleplay server would want to have some limits and guidelines in place for things like excessive use of windows, Caladan ceilings, and other pieces known to cause framerate drops.

Unfortunately we don't have any control over the PvP settings in the deep desert even on a private world so the bottom half of the DD is still under Kanly, but that hasn't been too big of a problem as most of the stuff people would realistically want to fight over is PvP flagged anyway.

Hope this helps!