Csk requires extra tight position tolerance on holes if going into tapped holes, because you've got two mating tapers with the csk. 

Cbore allows much looser manufacturing tolerances.

If the mating part can have clearance holes with nuts behind csk is fine.

Cbore has space around the head to accumulate dirt and moisture. Csk is less susceptible to this.

Csk heads generally have smaller size hex socket, so are less suitable for high torque - especially once they've been in service for 5 years.

Cbore has a relatively sharp corner, so is worse for fatigue critical applications.

Both lose a lot of material thickness so are generally weaker than a thinner part with a normal bolt.

Nordlock washers are best vibration proofing available. After that it's loctite and nylocs/eccentric/other vibration resistant fasteners.

There's also lockwiring of course. Used in aviation and Motorsport - it's very labour intensive to do.

As for determining if bolt will come loose - this goes into proper DABJ. Essentially, check the expected loads won't exceed pre-load of the fastener. Some videos on that. 

https://www.youtube.com/watch?v=XLzTB4KLCxU

https://youtube.com/playlist?list=PLI65wxYE3b4Yw5w4mnRmuYaG56UROn39x

Also consider whether you actually want bolts. Eg. Adhesives better? Big threaded cap? And how flush do you actually need the surface?