What are the pros and cons of Sword>Pel>BarbC3>FencerC2 and Sword>Pel>HighC3>FencerC2 in both PVP and PVE? I kinda wanna do both PVP and PVE and i want to pick a build which has a great balance between it.
the difference isnt huge, with barb you get smoother leveling and some nice stuns and flat attack buffs. With highlander you get ignore defence for all types of damage (but you alrd have a no downtime pierce damage def ignore at fencer) which is pretty good for party play and skyliner which tbh is just a slightly better flanconnade. If you want the highest dps possible highlander is probally better while providing great debuffs for the party. Barbarian however has nice cc skills and dont have any skills that clash or are somewhat similar to fencer skills. Personally i find the barbarian variant to be more fun 
I took a slightly different path, but really close to what you’ve mentioned on the barb variant.
sword>pel>barb>barb>cor>fencer
Barb is really fun once you get seism. swashbuck > wait for enemies to get near while guarding/kiting > switch to 2H sword > seism.
I took corsair instead of another barb because I dont really like the upgraded berserk/warcry and the new skills got a really long cooldown. Corsair also gives me hook which is a very useful tool for pvp whenever i feel interested. jolly roger is also there to help for pve farming