Over the years many researchers have specialized in certain events like proving that Oswald could not have come down the stairs without being seen, the inconsistencies in the autopsy report and the impossibility of the snipers nest.
Most often our subject of interest depend on our background. In my case, with partly military background, I still find the snipers nest impossible.
It's difficult to explain to others and if you are finally able to, so what? Where is the smoking gun?, Who pulled the trigger? Besides, in case that you commit one single mistake all your work is worthless.
Of course there are also researchers who find excitement in naming shooters all over Dealey Plaza or making points based on politics or other personal bias.
In any case I mostly prefer to use method C as described above yet appreciating the enormous work of others on both sides of the fence.
The reason for my three "nightmare" questions will appear in another thread ...