As to the red tinge, it depends somewhat on the brightness of the red focus light, but generally you will need to keep shutter speed at or faster than 1/125 to cut out the ambient red light. With lower brightness of course, it is easier to eliminate that ambient red light. I use a red focus light quite a bit at night and find it helpful with skittish animals. I try to use the dimmest light possible.
I don't use the S&S strobes but believe you can connect each strobe to the housing via the "slave sensor" and not use the "additional strobe" socket OR you can connect one strobe to the housing and run the other as an additional strobe. I don't know the benefit of one method over the other. Maybe someone with YS strobes can provide more illumination. (Pardon the pun)