Actually, Egghead is back to being alive and well. He last appeared in the most recent Antman series. If I recall correctly, no explanation was given for how he's alive.
Egghead's more of a Hank Pym foe. I was very disappointed he was resurrected (I wonder if his niece Trish Starr knows).
Besides Crossfire,Clint has a few other enemies of his own: Trickshot (his mentor, along with the Swordsman),The Death-Throws,The Bullet Biker,and Bobcat & his Claws. A lot of these baddies haven't been seen in a long time.