I am currently lvl 80 and working on gearing all the way up. I am viable in “The ruins of orr” but far from having anywhere near the best gear.
The karma farming around the bases needs some tweaking. I find that the drop rate for me when there is a lot of people there is really low. I figure it is because I am not able to do enough damage to get any credit. When I am out on the map the drop rate is fine. If you adjust the drop rate lower on the karma events but also decrease the damage needed to get credit it will help the people with decent gear keep up with the others who have full top end gear and can dish out a lot of AOE damage.
To encourage map exploration away from the nodes and also party play you can have veteran packs which have a higher chance to drop good items/materials but are away from nodes and thus in low travel areas.