Have you got good bulbs for your room yet?
No they're not!
Your prints are what they are. They never change. Either the light you're viewing them in is too warm, or your screen is too cold.
5000K lights should be good. How do you think their light compares to daylight?
Yes, calibrate in dim light. But of course compare the prints to the screen in good light afterwards.
Gosh, well done!
I agree that the lighting works better at the RHS, but it's no biggie - go with where they want.
The question I have is, have you sufficiently damaged the digital photo to match the quality of the scan? May I see a 100% crop?
This is not a crooked problem. You weren't square to the row of people. You should have moved to your right a bit.
So I figure you'll have to distort the perspective and hope for the best: