Originally posted by DBCherry
I happen to think that rubber band wing mounts are a plus in a trainer. They can let the wing move around during a cartwheeled landing, or if the plane flips over on the ground. I really don't think it's worth modifying the existing wing mounting though. (There's a lot of guys out thee changing from rubber bands to wing bolts! 
)
I'd also leave the tank mount as is. If you have a leak, deal with it then.
Dennis-
I would have to agree with DB, in that the rubber bands are going to give you the flex and forgiveness you might need in any mishap. As for the tank, if it's already in, don't worry about it. If your concerned about leakage, remove your engine and coat the firewall and engine mount area with thinned epoxy.
Enjoy!