Feel free to add back SkinRestorer and see how it goes. If things are still smooth sailing, then go ahead and put back in Citizens and the other related plugin and see how it goes. I was hit and miss with Citizens plugin on my server. It seemed fine for awhile and then as the player count went up, the TPS started dropping and I’d remove Citizens and things would return to normal. I’m not a a plugin developer, but it seems that Citizens has some interaction going on with everything being done on the server, and perhaps with a NPC plugin, that is the only option, but doesn’t seem like that would really be the case.
View Distance and Mob numbers alone, might be good enough to increase your TPS. But any LAG plugin or stacker plugin, is going to be added processes to monitoring entities that is already horribly programmed, so the last thing you want to do is to put something else into the mix that either increases entities, or something that is snooping in on entities like a lag plugin.