I’ve seen helicopters with Jet engines
Nearly all (and certainly the vast majority of military helicopters) are fitted with jet engines.
SRBs are the unsafest vehicle ever conceived. Helicopters are in the top 10. I don’t think combining them is a good idea
Depends. You're both thinking Space Shuttle SRBs, 500t monsters with millions of lbs of thrust. A JATO/RATO bottle produces a few hundred lbs of thrust and all it's doing is assisting the helicopter by reducing the weight that the rotors are having to lift alone. I don't get why that's such a mindblowing concept.
Dunno about helicopters being that unsafe. I've seen studies that show helicopters to be safer than your own car.
And SRBs aren't that unsafe. They light, they go and they're very consistent with it. SRBs are only unsafe in that you can't control it, not because they do something unexpected that often.
Mixing them is only stupid if you don't know what you're doing.