I'm gonna start some overview of l2 classes and suggest some changes. First of all this game has way too many classes. Ofc in reality there's less than 1/2 of 'unique' classes but it doesn't matter because a lot of classes are just out of the game. Secondly balance is a big issue in l2 because of too many classes.
Archers
Arbaletist is a true example how fantasy archer should look like. PvP should be bassed on skills not arrows and uber high crit dmg. Archers PvP crit dmg should be cut in half or more(actually to the point where skill dmg > crit dmg) while at the same time adding new skills similar to arbaletist and making them skill bassed pvp chars. As it is now archer is a kid class because it requires ZERO skills to play. Every m0ron could play archer.
Skills like hamstring shot should be changed to fast casting debuf with high land rate.
Daggers
Another OP class like archers but this one requires some skills to play. To make them less OP crit dmg modifer should be removed from skill formula(this also means crit dmg reduction buffs/tanks heawy armor won't work). By removing crit dmg modifer from skills you need to add some skills like bleeds/poisions with high land rate and strong effect.
AW is the best example but skill like poision should be changed to instant cast and physical debuff. For example debufs like critical wound could increase skill dmg as well as dot's dmg.
Summoners...
..or total joke class. Seriously they can't do a **** as being a summoner but just summon some funny things that are almost useless in mass events while at the same time they're OP in 1x1. In my opion Necro is an perfect example how true summoner should look like. Summon shouldn't be main weapon, it should give assitence, summoner should be main power.
All summons should be nerfed on stats or pvp dmg reduction should be increased further. By loosing that summoners should get new skill sets with high power high land rate debuffs, dots and main attacks(fire/water/dark). JUST PLEASE DO NOT ADD HALF POWER PROMI/HYDRO BLAST think smth new... Also summon could have pasive agresion which only works then summoner is attacked.
Melee DD's
Tyrant/Berserker/Gladiator is an perfect example how melee damage dealers should look like. Also I could add and warlord to this section because with a completed skill set and new skills warlord can deal about 8000 dmg in less than 10s and mass stun etc...
Low dps melee DD's like dwarfs should get more skills that neutrolazes their targets while at the same time get some skills that deals good amount of dmg.
Healers
Seriously this skill link thing is a joke... Instead of making them unique you make them the same... Bishop is a pure healer which is ok and it's almost perfect while EE/SE is by far not! Instead of making SE = EE you could add new type of heals.
I liked SE skill bless the blood which is very good! but just few things: Power of this heal should be affected by heal increasing buffs, overall heal power should be increased. SE should be made HoT type healer. Also greater heal power should be increased and HoT effect should be done under 5s.
Buffers..
...they buff and whats next? Allmost all they can do is just die. Imo they should have instant transformations with skill sets that can kill people.
Tanks
Well they're ok as they're now. Just some useless skill changes should be done.
Mages
Another OP class that should be redone to less OP by adjusting damage done in pvp. SpS is an pefect example of what mage should look like. Making DoT's more effective would make him a pefect mage also it would require quite a lot skills to play a class well. Other two mages should get similar dots/debuff skills like SpS. Necro should be considered as a dark summoner or w/e not a nuker.
Well anyway I just needed to spent 30 min not falling a sleep :D Just my 2 cents.