Relative to stretch, testing shows that it is not whether it is flouro or mono, the stretch is associated with specific line characteristics. So forget about that attribute of FC. Everyone has their own opinion, but there are a few characteristics of the lines that are not opinions, but are scientific facts. One is that FC sinks since its specific gravity is 1.5 times that of mono or braid. therefore it sinks better than the others, and is not suitable for surface lure casting. Another is that braid has almost if not zero stretch, and a much smaller diameter for the same pound test as mono or FC, so it is good for situations where you want max sensitivity, or ability to feel subtle bites. And if trolling or long casting, due to its small diameter, it will more easily allow you to go deep.
It is my opinion that FC is less manageable than mono or braid for both spinning and bait casting setups, but that is not universally agreed to Some can make it work, and others, like me, cannot. I will use it only for very specific applications, and at the lower pound tests. It generally is quite stiff and harder to manage than the other lines.
I don't think many will argue that FC is more fragile than the others when trying to free a backlash. When it gets a little kinked , it will break.
Braid takes specific knots to hold properly. It is slippery. Same to some degree with FC. Lubricate all knots with all lines, but FC is really sensitive to not doing so.
All lines have their strengths and weaknesses. I personally think that FC has too many weaknesses to justify it in most applications.