Hey @bennett-family!
I happened to be alongside @morganwriter1gmail-com on that ACTION photography workshop. It’s great to run into her often on these forms.
I actually had the opportunity to use one of James Staddon’s (or his assistant’s) lenses for the event, and I actually found the opposite of what Morgan was saying. The 24-70mm f/2.8—not the 70-200mm—ended up being more useful to me. I found I felt very limited when I was using the 70-200mm. There were times when I was itching for that extra reach, but most of the time I was able to grab the shots I wanted with the shorter lens. I was using a 1.6x crop sensor camera (a Canon 60D… and I don’t remember what Morgan was using), so that may contributed to my desire for the shorter lens. I think if I had been walking around the super crowded vendor hall with the 70-200mm, I would have had a lot of shots I would have missed because there would have been more people in between me and my subject.
However, you’ve got an 18-55, and a 55-200mm… I think I would primarily stick with the 55-200mm. It feels like the 55mm end might be wide enough in the event that you find yourself up against a wall (literally), and you’ll love having that 200mm option to get in close with out actually getting in close.
About using shutter speed mode… I personally—who am not a professional and haven’t tried using it for an event—wouldn’t use that mode. Maybe it’s different on a Nikon (I was playing with my aunt’s and it was getting a bit frustrating 😉 ), but on a Canon, I use aperture priority mode (like @jamesstaddon taught us at ACTION) and then change my ISO to get my shutter speed to closer where I need it. If it’s too slow, I boost my ISO. If it’s safe for me to dial back my ISO because my shutter speed is faster than it needs to be, I’ll do that. I read an article once that explained why shutter speed mode is practically useless. The author’s main point was that it really doesn’t matter if the shutter speed your camera sets is 1/125 or 1/500. If something is frozen at 1/125, it’s likely also going to be frozen at 1/500. If you lock off your camera at one of those, it forces the camera to compensate by changing your ISO (which could be acceptable) or changing your aperture (which messes with your depth of field).
Personally, I would stick it in aperture mode, leave it there, and either boost or lower my ISO if my shutter speed is too fast or too slow. I won’t be caring too much if it’s at 1/60 or 1/80.
Hope this helps some (I’d give you more, but I have to leave now!)
—Logan