I liked how old Ash worked with sergeants (?) patrolling it so they could walk on you while you were whacking a scout. HIgher-level areas shoudl have something similar, nost just static mobs.
Yes, that is very true. Intelligent, dynamic mobs are very good ideas. Mobs that act realistically...shout to alert others, block exits if they're winning (using the same block code players use, not a silly auto-block)...things like that.