Well clearly I'm wrong, but it works for me. I have a night rating but don't really ever use it so the red light isn't an issue for me.
Interesting how you say the red writing would dissappear though. Wouldn't it just appear black under a red light? Otherwise quite a lot would dissapear off the map... like danger zones and some airspace!
I used to do a lot of black and white photography, and enjoyed mucking about in the darkroom - which of-course is pure red-light.
One day (you'd never do this twice!) I wrote all my instructions to myself in red biro. Once in the darkroom, everything set up, red light on, main light off...
... and I had a completely blank piece of paper. Totally impossible to even see that there was writing on it.
Regarding the chart/torch, it probably depends upon the chart and the torch. But you don't need to go flying to find out, try them together in a darkened room at home.
G