I am a strong proponent of using rubber bands on a trainer.

It is not unusual for a trainer to bump a wingtip on a fence, or pole, or whatever and the rubber bands act as a shock absorber.

If you use nylon bolts, I promise that a similar bump will result in a split fuselage.

That having beed said, 14 rubber bands seems a bit extreme to me. I usually use 5 on each side, and then one one each side in a criss-cross manner.

I would also suggest that if you have the option, go ahead and install all of the "Bolt-on" options so that in the future, if you ever decide to switch it, it will be easy to do.