1. No, frantic flame has overall low stats for a mythical, plus it adds 81 heat per shot, so definitely not worth it if you want to avoid shutdowns.
2. Energy hysteria on a heat mech? Come on, you're better than this.
3. Putting any extra weapon in replacement of last words will make your hysteria useless 90% of the time since you don't have a weapon to push them back. One thing to note when making a mech with hysteria/savagery is-
For example:
One distance generator/anti close range. (Hammer or recoiler)
One push back weapon. (Last words, repulsers)
One range 3 weapon to secure all the ranges.
As for drones, you already have good ones for now.
It's called workshop unlimited.