Musket/Mage build?

[Wu]

I've been doing a lot of the quests for the mages in Tanaris so I could join the guardians, and one quest brought me to Tacarigua to the inquistors. I want to buy a musket from someone in the camp, but it says I need "gunsmith" perk or something like that. Where do I get said perk, and does a Musket/Shotgun/Mage class make sense? My reasoning behind it is that I can use magic for long range attacks, and switch to shotguns if enemies get close.

[Applied Mediocrity]

"What's better than a mage? A mage with a gun, of course."

I haven't played it that way but you should not need any perks to be able to use guns. Gunsmith is for upgrading guns (and isn't that useful, I think). In fact you don't even need skills - a good mid-game musket will be reasonably effective even with 0 Musket skill (aim and reload speed) as long as you invest in Ranged points (damage). Now, if they don't sell any for some weird reason, just help yourself around the island and you're bound to find one, for free (hehe).

The only downside, if obvious - guns run out of munitions rather quickly. Be sure to stock up.

[Smaloki]

The guardians' magic can be used for both ranged and melee attacks (you can't block with magic, but you can't block with a musket, either - smaller enemies will be knocked back, but attacks from big enemies have to be dodged).

That doesn't mean that you shouldn't go for it - early on in the game, muskets/shotguns are significantly more powerful than magic. And if you run out of bullets, two-handed fire weapons can still be used as clubs (yes, you can actually use it to beat up enemies - although it's not very effective, especially if you've never put any points into melee).

Honestly, as long as you don't play on ultra difficulty, you should be able to get through the game no matter how you built your character. Worst case scenario, you just lower the difficulty setting until you've leveled up your magic to the point where "common" enemies pose no threat whatsoever.
A musket/mage combo definitely sounds interesting - if I were you, I'd go for it.