securing PEX lines

Since replacing my hot water lines with PEX I've noticed a trend that makes me wonder.

When routing PEX lines, is it a good idea to secure them to the wall, as in a PEX to threaded pipe connection. I've noticed that the hot water in the PEX has a tendency to make it grow and shrink, but not necessarily in a straight line. Oftentimes it'll grow and twist in a spiral motion, pulling the hose it connects to or bending at a weird angle. I'm concerned because when I finally patch the drywall and secure the PEX tubing to the studs that the extra restraints will make the PEX grow unnaturally and burst the line, or it will rub against one of the channel guides and wear it away.

What kind of channel guides should you use when securing PEX pipe to a stud,

1 every 18 inches, one every 10 feet, don't worry about it, or does it depend on code and the specific situation?

Another issue you should think about is noise caused by expanding pex rubbing against other materials. The pex I have installed (Viega) comes with plastic hooks with ring shanks---easily attached to studs etc. But, I have had issues with 3/4" pex rubbing the hooks and making irritating sounds. At some point I pan to re-install the offending hooks with a dab of silicone in them between the pex and hooks. I probably should have put silicone on in the first place. Viega calls for silicone in heat transfer plates used for radiant pex. I was generous with the silicon in the plates when installing and have not heard a peep from them.

Fine Homebuilding has an article on pex in the recent issue.