Marmalady,
Basically, no. The qualification is there because sometimes "free range" can be "heirloom" as well. Also, just as an FYI, there are all sorts of degrees of "free range," some far freer than others.
If that's what you like, it's fine. I use my instants for nearly everything -- but prefer to use something that can be left in, with an alarm, for long cooking because it prevents overruns. The one I use has a wireless readout which allows keeping track from a different room.
We do ours the same way, mostly because we smoke our birds.
Some other thoughts:
With all respect to Chef Ray, IMO there's no need or benefit to clarifying the butter for either (a) rubbing compound butter under the skin; or (b) incorporating melted butter in the injection. The turkey will never get near butter's smoke point -- either under the skin or in the muscle -- so I just don't understand where he's coming from. I've never heard of clarifying butter for either purpose. Of course neither my limited awareness, nor lack of understanding make him wrong.
Speaking of butter in the injection, it's not at all a bad idea. So props to Chef Ray for bringing it up. Also, instead of butter you might want to try a flavored oil -- ideally truffle. If you do use truffle oil, remember that a little goes a very long way.
About the brine/marinade issue. There aren't laws about language use, so no criticism intended... Properly speaking, all brines include a fair amount of salt; all marinades have an acid component. Brines usually have some acid, too. Marinades usually, but not necessarily, also include fat; while brines never, or almost never, do. [I can't think of any which do, offhand. But, "One never know, do one?"] In fact, besides salt content, fat is the thing we first look at before we say "marinade" or "brine." Either may include a sugar component, but that's more common with brines.
In any case, it's a chemical differential between the marinade/brine and the food to be marinated brine that powers the "diffusion" processes (which may or may not include osmosis), which allows the brining/marinating to do their work. From a culinary standpoint -- if you're looking at the amount of time it takes to get flavors into the meat, saline differential is the most powerful, then acid, then sugar.
Another difference between marinades and brines is that while both can bring all sorts of flavors, brines are more intended to moisturize, while marinades are meant more to tenderize. It's the acid which does the tendering. In turn, this goes to your comment about a citrus marinade "cooking" the turkey. With the marinade set to any reasonable amount of acid, it's not something you really have to worry about.
One of the nice things about making marinades is you can usually rely on the general rule that a good marinade tastes good. So, dip a finger in before you marinate and you won't go too far wrong.
Feeling holiday information overload yet?
BDL