I've used a Storm saltwater Chug Bug and it's my understanding that they should be retrieved at a slow to medium pace.
If there are Bass about though, don't be shy - they move very fast and will chase a popper on a fast retrieve.
I'm not sure about spooking fish I wouldn't think so but watch out for seagulls - they have incredibly keen eyesight and will spot a surface lure from miles away.
First time I cast my Chug Bug out I looked carefully for signs of gulls and, seeing none, I was horrified when after about ten yards of retrieve, the wake from the lure was surrounded with 'em (all shouting 'mine'!).
I did a 100 knot retrieve and managed to avoid them but, that aside, surface fishing is great fun and a take from a fish is monstrous!
Good luck.
