oh hectique!
I enjoyed the game for the most part. I actually preferred gliding over flying oddly enough (probably because I kept dying when farming airnodes with my lag) ... traveling just got to me. Pay half your savings to fly to a checkpoint, then by the time you run to your quest point where you died, all the mobs have respawned and you get pwned again :/
Having said that, I thoroughly enjoyed my sorcerer. My assassin and gladiator only just made it past ascending.
Do you still have to do the epic quest lines that require group play to get through to certain areas in the game?
Well ... to address your first points - the cost of travelling is still the same, but making money is much, much easier. To put it in perspective - I have a level 13 character that has just under 100k in her personal cube. And campaign quests tend to reward you with a fair amount of kinah as well (not sure about the lower level quests - I'll check - but level 40+ campaigns pay upward of 200k).
A lots of items are also in high demand - specifically Critical Hit, Magic Boost and Attack Manastones, even the white ones, and you can generally see them selling on broker for 90k+. So if you get a drop, you put them on broker, they usually go within an hour. Those are the white stones. The prices on green stones are ridiculous - I've made plenty of kinah on those.
Sorcerer tends to be quite tricky at lower levels especially - you have limited spells after all, and they call them glass cannons for a reason. That being said, I'm at a point now where I can easily handle 2 or 3 high level mobs without too much of an issue - takes practice, but its doable - and critting with some of my spells gets rid of half their HP easily. Add Root, Curse of Roots, Sleep and Winter Binding - you're good to wipe out groups.
Gladiators are absolutely mean - you get AOE skills down the line - I've seen some of the better PvP glads run into entire groups and do major, major damage before dying. Sins are also fun, although pretty challenging for us because of our high ping. I tend to go for asmo sorcs and spiritmasters if they're silly enough to let their stone skins drop - I can generally wipe one out in about 5 seconds flat.
Getting to your last question - yes - the campaign quests are still there, and it can be hell getting groups for the lower ones, but with 2.5 they've implemented the mentor system - it lets you group with high level chars, they can help you through those quests, and it lets you get all the xp and drops - they don't get capped at all. I've mentored a couple of lowbies already - and if you only take one or two in the group and drag them through an elite area they get mega xp. Some of the campaign quests have alternate routes you can take to complete them as well which make it somewhat easier to solo them - not too easy, but if you're careful they're doable on your own.
The only thing you'll really struggle with if you come into the game at this point is if you get your character into Heiron(Elyos)/Beluslan(Asmodian) - NC has implemented a rifting buff that gets switched off every 2 weeks, so if you're undergeared you usually have a week of relatively undisturbed questing, and then a week of absolute murder where you can't do anything. There are epically geared level 50's running around there, and they kill anything that moves. I'm actually busy gearing up my cleric at the moment, specifically to hunt them - and its tons of fun, provided you're good enough to get them dead without dying yourself.
Seriously guys - if you have questions, pop ... I have tons I can write
