"The Bass Player's Role."
How would you feel playing with a drummer that consistently leaves the beat to play fills all over the place? I mean constantly playing fills and rarely playing the beat, leaving long stretches where the beat is either implied or the guitar bass or keys need to cover that beat?
How about playing with a guitar player who just noodles over the top of everything, regardless of what else is going on?
In a pop/rock context- (as if I haven't typed that phrase enough in this thread) instruments have a defined role within that context. Regardless of whether you may consider it a "stereotype." It's generally how things roll in a pop/rock context.
You mention Lee and Harris- both of which I'd consider pretty "traditional" in the "role" of the bass player. Both very melodic, both busy, both notey- but still very traditional and IMO play with the utmost taste. In what they're doing, their busy-ness doesn't remove them from the bottom end of the spectrum, or the rhthm or "groove." Their playing is a part of it, not separate from it. I see very little similarity in the style of Entwistle vs. Lee or Harris.
I specifically said the bass player does not need to be tied to the root:
If you've had more than one discussion with your bandmates about the role of the bass (and thus, your role in the band), you may wish to try to objectively view what's going on. In playing in a pop/rock context, the ultimate goal is to provide/create a cohesive piece of music. To those ends, "expression," ego and technique take a backseat to taste and competence.
BTW, I'd be fine with 10 frets and 4 strings.