Didn't read all the posts so this may have been said: if the BB is French, the right cup will be right-hand thread. This means it will be self-unscrewing so it will have to be considerably tighter to not unscrew on the road. I found getting them tight enough to be at the limit of my hand strength and willingness to injure myself when I was 24 yo. I used to hang my frame from the ceiling, clamp the BB cup in a large bench vise and tighten or loosen using the frame as a gigantic wrench. (You need clean, sharp vise jaws to do this.)

Another approach is to use a good BB cup wrench and a long bolt with fender washers running through both cups to keep the wrench from slipping.

Ben