How is Ranger or Dervish?

Any profession is capable of soloing. Some professions might find it easier, but all professions can do it.

Henchmen take their share of the loot. Whenever you pick up some gold, that gold is divided equally among all party members, regardless of whether they're human, henchmen or heroes (think of heroes as customisable henchmen that you can pick up in Nightfall). When items drop, they are randomly assigned to party members. If an item is going to be assigned to a henchman, then it just doesn't drop (I think it disappears into Hammerspace or something). So being in a larger party can potentially reduce your gains from adventuring, but if you can go without henchmen then you're under no pressure to use them.

As far as each of the "jobs" go, here's my opinion on each of them. Some of them are more useful in the party than others, but none of them are useless. All of them are also great fun to play with, so pick one that you think matches your style and see how you do.

Warrior: Best armor, great damage, pathetic energy management. Also a monk's worst nightmare if the warrior in question suffers from delusions of invincibility. Virtually every party will want at least one of these, and also a very easy profession to learn to play with.

Ranger: Decent damage, great attack range, option to get a pet for extra damage, arrow preps to enhance their normal attacks, and able to change the laws of nature in the local area (can be a blessing or a curse). When it comes to strategically pulling mobs, they're second to none. Many parties will want one of these.

Monk: The game's primary healer - 'nuff said. One of three professions that have reusable rez skills. Every party will always want a monk or two, and I for one refuse to leave any outpost without one.

Elementalist: The game's primary nuker. Amazing damage output and highly versatile, if not a bit squishy. Also very easy for newcomers to learn the game with, and quite popular in parties because of their damage dealing ability.

Necromancer: In PvE, necromancers can be extremely popular because of their ability to raise undead minions that create a wave of destruction. Having one of these around is like having a "get out of tough mission for free" card.

Mesmer: Probably the least popular of the professions, as they're highly specialised and more difficult to learn. However, they can still be extremely powerful in combat (and can make mobs die for apparently no reason thanks to their unique skills). They're often overlooked and can sometimes find it difficult to get into parties, but that doesn't make them any less deadly.

Assassin: Requires Factions, and is capable of inflicting an insane amount of damage on a single target in a very short amount of time. Also the most mobile with their ability to shadowstep (short-range teleport) in and out of combat. Your best friend up against bosses, but not designed for sustained combat (if an assassin decides to try to tank he can go from being the party's best friend to their worst nightmare). Popular in certain areas nearer the ends of each campaign where bosses get much tougher, but often overlooked in early game areas.

Ritualist: Requires Factions, and also the game's secondary healer. Can be useful if there are no monks around, but they lack mobility and are perhaps best suited to situations when specific points need to be defended. Can also add some heavy artillery with their attack spirits, as well as having a coupla skills that allow them to rez themselves as well as others (making them the second of three professions with reusable rez skills). Far from a "must have", but very useful nonetheless.

Dervish: Requires Nightfall. Relies heavily on enchantments, many of which have secondary effects when they end. Able to unleash a whirlwind of destruction in the melee with attacks that hit multiple adjacent opponents as standard (which is gonna happen a lot in PvE), although they're not as durable as warriors. Plus they're the only profession that gets transformation skills, which are pretty cool to watch. Great fun to play with, and always a valuable asset to the team.

Paragon: Requires Nightfall. Highly versatile and very well armored, they're at their best in large parties as their support skills tend to affect everyone at once (and a few of their skills power up if there are more allies around). Also the third of the three professions with reusable rez skills. Perhaps not as popular as they were originally as they've been nerfed a bit since their introduction, but I still like having them around sometimes. Read this. Now read it again. You should be able to choose your profession.

PS: there are 4 character slots for the Prophecies campaign, 6 for prophecies+factions, 6 for prophecies+Nightfall, 8 for Proph+Fac+NF. And you can purchase them in the account store for $10(USD) per slot. So you can make many different characters with different professions.

PPS: You select a characters Hair Style, Hair Color, Facial Features, Skin Color, and height when you create them.