You have to buy your own arrows/bullets.
Most used subjobs are WAR and NIN, some over 60 use SAM.
It's an expensive job, if you can't afford it, don't waste your time on it.
Equipment is expensive and crucial for being a RNG that can hit your target.
All races are pretty much equal.
Elvaan : Look cool (apparently), high STR, low Accuracy (made up for with equipment)
Galka : Low AGI, great STR, pretty rare.
Hume : All around.
Mithra : High AGI/DEX, good Accuracy, reasonable STR, most common.
Taru : Low STR, high AGI, good hit rate.
I suggest going THF to 18, WAR to 15, then THF to 30 before you go RNG. That way you can sub WAR if you like, but have THF close to 45 if you want treasure hunter 2, at the least you'll have treasure hunter 1.
If you have no idea what I just said, I suggest you read, read, read, read. 99% of your questions can be answered by reading past posts in the forums of this job, and any other job you might want to look at. Read as much as you can about stats/abilities (listed above under the Description) for any job you have an interest in. You pretty much asked to know everything about being a RNG which would take way too long to post. Go do some reading up on it.
Your jobs stay at a static level (never change, unless you die and lose exp far enough to drop you down a level). Subjobs can only be half the level of your main (they're temporarily dropped, but remain at the level you got them to, so you can always go back to them). You can change jobs whenever you want.
Hope you enjoy RNG.
Edited, Sun Feb 29 19:53:44 2004 by defunkt