When training with a Kung-Fu staff, should I keep a strong grip on the staff or a loose grip?
*by training I mean doing basic staff exercises such as rotation or simple movements with the staff.
For most staff work, grips change constantly to change range and direction of attacks or parries. You have a tight grip when you expect impact, and naturally, you have to let go/slide/keep simple contact when you are moving your hands to change grip position.
If you are working from a form or in a class, this is something that should be shown to you.
If you are trying to play around and figure it out on your own... well, you might do well looking up some videos and books to see what your options are in terms of movement and not go fast or hard to start, especially if there is a chance the stick might fly out of your hands and hit anyone or anything that can break.