Absolutely safe. They also look neater and are easier to maintain than rubber bands.

On a .40 size plane, the most you need on the wing is 10-32, unless you fly pylon. Drill and tap the bolt blocks with a 5/32" drill and a 10-32 tap. A #21 drill is actually the proper size, but the 5/32" works well and is easier to find. Soak the threads with thin CA, let dry. Re-tap. Do this again. The threads will never pull out.

On the landing gear, I'd use 4 10-32 or 3 (two in front, one in back) 1/4-20 bolts, depending on how soft your landings are.

Dr.1