This is an excellent question. The Professionmal inquiry will be taken care of in a seperate post, but the Hacker question is detailed here:
The /+ BAB for the Webcrawler is exclusive to that class and the True Hacker prestige class (this P-class's BAB bonus stacks with it). Other classes do not increase the latter BAB (the immersive one), but if a Cybernet character's normal BAB exceeds their immersive BAB, they can of course use it instead.
Games Masters are always free to rule that certain P-classes will increase the immersive BAB as True Hacker does, but in the basic rules, only True Hacker does this natively.
-August