How often are you needing to change shutter speed?
It shouldn't take seconds to do it.
If time is really such an issue, you could always try using Shutter Priority and it wouldn't take any time.
What you are seeing is the only option.
Hmm ... my Nikon has smaller increments.
The shutter speeds offered go: 1/15 1/20 1/25 1/30 etc.
I'd be surprised to see many cameras with 1 stop increments
Did you not see what the OP said about his intention of flying ~300-400' over a suburban part of town?
Did you see what I wrote in post #4?
Why would there be any involvement of an investigator?
You are over-dramatising something that's nothing.