1. 'Lights, flashing lights. She don't believe in shootin' stars'
2. Speakers phone could be funni. Also could be mingey.
3. So in a sense, if a cop is around, catches you and you have to risk a PK to kill him to continue your RP. You successfully roll the dice and kill him. You want the cop to be able to yell/possibly radio for backup? Presumably at the range you're speaking, the gunshots; even silenced would be enough to indicate to cops close enough. Making this redundant for how you suggested it and brokenly overpowered otherwise.
As for tools.
Spikes, could work but I feel like people would just continue to just drive with the popped tires In their bugatti's and ferraris and still get away from cops. Also I'd have concerns if it's done improperly could just end up blowing up the vehicles, or used to grief buildings. I could see something where it's possible to request one for an ongoing chase, but to just give them to every officer to use, I'd probably be less for ( i know you said cpl + ). On the other hand, you could always just make them stupidly expensive. 10-20k per strip or limit them to ESU flags.
Pepperspray, if it incapacitates its essentially like the tazor, for just bluring their vision, sure but the range would need to be close. If it is close range, friendly fire needs to be taken into account, not to mention accidently pepperspraying yourself for running into an area you just peppersprayed. If they are running away and at a range, and you're not affected. Its essentially an overpowered flashbang and you'd quickly end up with broken PVP and people abusing (possibly through walls).
Batons to break bones, would 1000% just be abused by every single probie and cadet around and probably become a problem very quickly, maybe just have the right click baton pause their movement for a second or split second longer if this is really problem. Cops are already exempt from being PKed for the most part, which already gives them the immunity to go into situation that wouldn't make realistic sense. So cops on any detainment are gonna break peoples legs 'so you can't get away' or 'just incase', sure IA whatever, but this seems like a problem to me.
Aswell as, if a cop did break someone's leg, have they now started a violent altercation? Giving the crim a chance to shoot and die without pk repercussions? 'I'mma just run around until the cops break my legs, oh I can shoot now.'
Criminals need a chance, it's already favored for cops and it should be favored for cop. But a delicate balance needs to be considered, at a point you might aswell just have the teleporting baton stick if there's literally no chance to get away, not saying your suggestions would cause such an imbalance, just that it needs to be carefully considered.