Already lost ED-E.
Boone won't follow me, I shoot him and he moves a few steps.
I use the pushy on him.
Nope.

Fire and rehire him in the same second,it should reboot him.If not fire him and let him return to Novac then wait a few days and go there,he may be in the Dino mouth waiting for you to hire him again.Also,depending on where he's spazzing out,try fastwalking to the location you are already in,like Primm to Primm and it may release him.

Could have said it better myself. They tend to get stuck in hilled areas or stuborn after a while.. though I must say id hope u didn't get ede killed.. if so id tell you to save more often

I think your reputation has to be good also. If you're vilified by the NCR, I think he won't follow. Anyone please correct if I misremembered.

boone is a pain in the ass
he wont follow if your friendly with the legion
he wont follow if your friendly with great khan
he wont follow if your friendly with the brotherhood of steel
he wont follow if you are vilified with the NCR

his perk is pretty useful but he is to much of a pain imo
especially when i ran my im idolized by everyone but the Legion Campaign

also if he has ever stopped you and said
"im not gonna follow you if your attacking NCR, i may not be a Ranger anymore but they are still my brothers" (he said this to me after he slaughtered 10 NCR all on his own, i didnt even have a weapon out)
"im not gonna follow you if your gonna get all chummy with Caesars Legion" (he said this to me went i went to go find benny in the fort)
"im not gonna follow you if your gonna be friends with those Brotherhoods" (he said this to me when i was investigating the hidden valley bunker)

when ever boone stops you and says something listed above or something similar about other factions you are given 3 options
1.ok, im sorry. it wont happen again (this lets you keep boone as long as you dont get any friendly with that faction)
2.but if i can infiltrate blah blah blah.(boone will reply "i dont care i wont play nice with them for any reason!")
3. fine, leave then (boone will leave and you will never be able to get him back if you try to recruit him again later he will say "i dont even know you anymore..."