Third edition Traditions, Crafts, and Orphans form the human player-character “norm” for mages. In terms of game-play and simplification, if your character hasn't learned magick in the style of a Tradition or a Craft, the character will probably be considered an orphan.
Starting characters are generated with the standard numbers, to include the standard 15 points of freebies. Keep in mind that starting characters will have an Arete of 3 or less, and a sphere rating no higher than their Arete.
Most flaws or merits are allowed within the scope of the character concept with sufficient justification, within limits. Note that certain flaws or merits may be restricted or disallowed without a compelling justification in order to preserve the balance of the game. While flaws and merits will not necessarily provide the basis for a new (or continued) story line every week, consider them fair game for an ST to exploit at an inopportune moment to keep life "interesting". On that note, don't pick flaws or merits you're not willing to have your character live with. If you take it and it's on the sheet that gets approved, your character will be stuck with it until he or she figures out a way in the game to permanently "buy off" the flaw... and typically, it's not a cheap fix.
As a mage player character, it's common knowledge among the Traditions and Crafts that ghouling by any means tends to be a real unhealthy choice. There's not really an explanation why (as if anyone needs a reason to avoid drinking blood, period!), just an admonition not to go there.
For the record, any player character may learn Do as a skill. Keep in mind that Do may only be taught by an Akashic Brother, and various Akashic schools have differing requirements for would-be students. As a rule, if you’re not an Akashic Brother, you must be able to find an Akashic Brother and convince him or her that you can effectively learn the Akashic paradigms to be considered for acceptance as a student. They're not exactly easy to find, much less convince.
Special maneuvers require special training; much knowledge has been lost in the diaspora. Non-rote special maneuvers can be learned by anyone. Do rotes, on the other hand, are jealously guarded secrets NEVER to be taught to anyone outside the Akashic Brotherhood. ONLY an Akashic may teach Do, only a Master would teach Do rotes, and no Akashic Master would ever consider teaching a Do rote to anyone but an Akashic Brother in good standing.