IIRC - yes, the donor 1.0 for enchanter is a dire charm that allows you to dire charm higher level NPC's than the AA (AA is custom on this server, can dire charm up to level 65, think the donor is 71-73 npcs or so.) Charming can be fun, but is typically not very powerful. Most raid tiers have charm-able NPC's near the entrance that are on quick repops, so if it dies you can trek back to the entrance in 10-15 minutes to recharm it. However, most of the charmable pets in raid tiers aren't super powerful. The donor robe adds a focus effect that lets you charm *any* NPC (besides mobs labeled as bosses/unkillable/etc.) which makes it much more useful/powerful, but I don't think I remember seeing anyone use it, so meh

As an enchanter, 99% of the time you'd only have one duty on raids: debuff. There are several encounters near and at end-game which *require* mezzing, but outside of those events you're pretty much just casting 2-3 spells and then looking pretty. Not to denounce the class, those debuffs are EXTREMELY powerful. But if someone has an enchanter box on the raid, you're pretty much just fluff. They have some nice short-duration caster DPS buffs, but there aren't a whole heckuva lot of raids that rely heavily on the caster DPS department... Though most people would love you for allowing them to /camp out their enchanter

In the end, just play the class you want to play the most. Afraid of being outclassed at tanking because there are 3-4 other tanks in your raid with better AC? Don't be. If those tanks drop, you're next in line and will likely be the saving grace for the kill. You can never have enough healers, and all three healer classes are good at what they do. Pets are very good fire-and-forget DPS from necros/mages (plus dots/nukes aren't too shabby either), wizards provide some decent bursty DPS (though they're mighty squishy...), and a set of enchanter debuffs will make or break any raid. As for the DPS classes, any and all are good. To me, DPS is DPS. Doesn't matter if you're doing 20k or 200k, that's 20k more than before.
If you're going to be soloing (no boxes), and really want to be handy to a group/guild/raid, I'd suggest bard. Single most underrated class on the server, and they're rated pretty high. And I haven't been on a raid yet where every single group had a bard in it. They're pretty horrible by themselves without some decent gear, but their songs for group are simply amazing.