It it possible to play as a pure mage or using mage as a utility/supporting tool more viable? I'm asking because I prefer to use magic all the time if's possible, otherwise hybrid is fine which brings me to my next question; I don't usually like playing melee warriors so could I play as a mage/archer type? If so, which faction is a good choice?
I'm using the v1.3 unofficial update.
At the beginning of the game you will need to rely upon your blade until you can find someone and the money to train you in archery. As you explore you'll find trainers which will be noted in your Journal (L)
With Risen, it takes time before you're in a position to train as a mage - it's not an option that is available immediately. But, you can purchase spell scrolls and cast them, so there is a certain amount of casting that can be done as you explore the island and town early on.
To train as a mage you need to be accepted into the Monastery. If you press C to access your Character Stats, you will see there are 2 forms of magic: Crystal and Rune.
Crystal magic allows you to cast magic Bullet, Fireball and Frost. At their strongest these are devastating spells, but different opponents come with different strengths and weaknesses, so if you train solely in Fireball it will be quite ineffective against opponents who are resistant to fire.
Rune magic allows you to create scrolls and again, these can be powerful. They also allow you to expand the range of magic at your disposal. The Seal option is the basic requirement for the use of magic runes without using scrolls i.e. you cast the spell directly rather than creating a scroll to cast if from.
Most of the trainees at and for the Monastery are shown using pole weapons, but I've played the game as a sword wielding Battle Mage which has been an effective mix. However, a mixture of Archer & Mage is possible, but will take time to develop. Playing the game as a pure Mage at the start is - imo - impossible. I would argue that Risen encourages a hybrid character build. Still, if we view the game as containing beginning, middle and end sections, a pure Mage should be effective mid game and for much of the last section.
The best route to get into the Monastery is via Harbour Town, but I'd suggest some exploration first (both outside and in the town) so that you can gain experience by doing quests for other factions before joining up - it's possible to milk this game for experience points at the start and it's worth doing.
p.s. There is a place where you can find a bow and some arrows early in the game. If you wish to use archery from pretty much the start, explore the land close to where you meet Jan.