Here is a science club we have in Australia called the Double Helix science club:http://www.csiro.au/helix/
The ideas you have so far seem quite good (not so sure about the "controlled explosions" I think the club could function just as well without them.)
What about field trips to "science type" places? Museums, Science Centre, observatory, Zoo, you get the idea?
Crytsal growing competitions are sometimes fun.
There may be grants available from certain places to help set up the club.