Allowing Medics to help Other classes in these situations

Since all people who have shot can flee afterwards, this would result in a lot of reports, about medics killing fleeing suspects. These will take a lot of time to investigate, while most of the reports will be invalid due to insufficient evidence. A bit like currently with cop hunt complaints.

Another thing is medics will get shot, when they are near a cop, as they basically pose a threat.

I don't think anyone will be happy with that, and in the end it results in moderators and admins spending more time on spectating users rather than have some fun, by either playing the game or organizing an event.

Last but not least I agree with Domingo. Medics should only use violence out of self defense. (Not even out of revenge even, as their job will give them advantages over civilians.)
Medics are medics, that's a perfect explanation to your suggestion.
No.
I think the amount of effort you put into this post is pretty cool but to not complicate things, medics should really just be healing players whether it be cop or criminal, imo.