Simple question

Can you have more than one role ascension? For instance, can my warrior/samurai become a warrior/samurai/ranger? Can I have as many roles as I want/or have stats for? Just curious.

Not at the same time (you have to choose one at a time) . . . your advancement in the previous role stops at whatever level you were at . . . growth in nonsupported magics is limited to half your skill level in that magic (i tink). It is good to view your manual and plan ascensions carefully (they state what skills/magics are supported by each role). Most people suggest you advance to a level of 10-14 before switching; being careful to get all the high level spells). Once you have left a role you can't go back. You start out as a level one in your new role and advance quickly but dont get points to add to abilities (such as strength) as well as only being awarded one hit point per level up . . . skill points are one per level too.

[carg]

Note that you can never go back to a role you've switched away from, and never to the basic roles.
You can still use all skills and traits from your previous role, with a restriction on magic as stated (you tink right Lily!)
That level 14 guideline for switching is mostly for spellcasters. If you're not planning to cast many spells with your samurai, there is no reason to wait that long. Do try to get burning haze (5) and preferably firestorm (7) too; they'll come in handy.
A few more restrictions: your ranger won't be able to learn new samurai-specific skills and traits, and not use samurai-specific equipment either. Most equipment can be used by both though, and there are still many skills and traits a ranger can learn at the bushi guild too.