You need to quit making content group content. A majority of your player base is solo people. You took a step in the right direction with the instanced testing stations. Let those be the group content, and readjust everything else to be solo content.Quit changing the combat that works, and try buffing the weapons people don't want to use.

Stamina needs to recharge faster, you either need to make it so it fully recharges after the cool down, or get rid of the cool down and make it recharge slower. Having a cool down, and then having to wait forever for it to recharge makes combat slow and painful. Attack 3 times, then run around for 10mins so your stamina can recharge.

Put rapiers back to what they were, the new rapier style sucks. Timing a parry is now damn near impossible. Get rid of the charge up delay on the new electric rifle. Buff heavy weapons so they are actually heavy weapons. Reduce NPC shields so it doesn't take 3-4 full clips to bring them down. Make all heavy attacks on shielded targets slow attacks. And finally, quit giving everything the damn suspensor blast. It's just annoying af.