Shoult style sheets be attached to the master style?

[ZiNgA BuRgA]

Up to you really.  I don't think there's any 'friendly' functions for doing this.
If you want to modify global.css, I'd imagine it's just editing it in the DB then updating the cache file (check MyBB's ACP code on how they do it).

(08-21-2012 04:40 AM)Sama34 Wrote:  the official MyBB support team gives an orange about your support threads

That sounds generous, unless the orange is perhaps more brown in colour.
Generally you don't get much (or worthwhile) support for more advanced topics.  Basic stuff typically gets answered well enough.