To be sure, the simple answer to your first question, "Would I be able to ski without doing the wedge? Can I jump to the hockey stop without going through the basics?" is a general but qualified "yes." But there is a lot more to the story, and frankly, if you are truly completely unable to develop internal rotation of either leg, it will be just as much a handicap for your parallel turns as for wedge turns. If internal leg rotation really is out of the question for you, I'm afraid to say that skiing may not be your thing. I suspect, though, that there are ways to develop the necessary movements, and if not, I agree with others here that you may well find snowboarding to be your winter sport of choice (you will need to be left foot forward or "regular"--not "goofy," which would require internal rotation of that right leg--and even there, special attention to your snowboard stance and board setup is in order).
It is not as simple as it may appear on the surface (like many things). At first glance, it sure looks like "parallel" involves legs and feet pointing straight ahead, while a wedge involves both legs internally rotated. But the fact is that in a parallel turn, the outside leg (the right leg in a left turn) will be internally rotated, while the other leg is externally rotated. In other words, like the wheels of a car turning left and right beneath the chassis, the legs turn left and right beneath your pelvis in ski turns.
That means that the right leg in a left wedge turn is internally rotated exactly as it would be in a parallel turn--there is no difference whatsoever there. In fact, the primary difference between parallel and wedge turns is that the left leg in a left turn is externally rotated less in the wedge turn than in a parallel turn. So any internal rotation limitation that would prevent you from making a wedge will interfere equally with your parallel turns.
Yes, people can learn to ski without making wedge turns. But they cannot learn to make "normal" parallel turns without the ability to rotate both legs internally (and externally). Although few skiers seem to understand this, the wedge itself is of little importance, but the movements involved in making a wedge are critical to good skiing!
Of course, there are ways to get around this limitation, sort of. Adaptive instructors work with all sorts of disabilities, including paralysis and other things that prevent or limit various "normal" movements. You can force your skis to "turn" with your upper body, by twisting your shoulders and torso first and then pulling your skis around, or by jamming in a forceful, forward-facing blocking pole plant. You can learn to get down the hill with these movements--and many skiers do. But compared with "normal" good ski turns, these movements are about as effective as trying to drive a car with a locked steering wheel by trying to turn the whole car. It would be difficult, at best, and even if you could do it, you'd still not be able to drive smoothly on a twisty road. In other words--and again, to your original question--yes, you can "jump straight to a hockey stop"--but hockey stops simply are not turns!
So again, complete lack of internal rotation in either or both legs will be a real limitation for your skiing--not just in the early learning stages where wedges are common, but always. (And misunderstanding as to why this is will limit your skiing too, regardless of your rotational range of motion.) However--and without any real evidence beyond a hunch and some experience--I'll bet that your limitation is not as complete or insurmountable as you may think. First, difficulty with a wedge at first try, with symptoms similar to what you have described, is not uncommon, and can arise from many things besides limited rotational range in the legs. Stance issues including leg length discrepancy or excessive pronation or supination of either foot, strength asymmetry, leaning to one side, twisting your upper body or pelvis (extremely common), poorly fitting (especially too loose) boots, trying to stop instead of allowing yourself to glide (a natural reaction for many people), a hill that slopes a little off to the side rather than in the direction you're going--these are just a few factors that commonly interfere with wedges (and subsequent progress) for beginning skiers. They can all make it seem like you simply, physically cannot make a wedge, as you have described. But with a good instructor, you will overcome these problems quickly.
If it really is the physical limitation that you suggest, solutions may still exist. Stretching and work with a good physical therapist may help you develop the range of motion you need (you don't need much, although the more the better). And some types of ski boots may help--although it is unlikely that you'll find these boots in a rental shop. Fischer's "Somatec" boots, for example, place you in a slightly duck-footed (externally rotated) stance even when your skis point straight ahead. They might work for you. See Bud's post above (or better--contact Bud himself) for more information about how boots and boot setup can compensate for many physical issues in skiing.
And then, of course, there is the snowboard option.
But the main point I want to emphasize is, again, that "hockey stops," while parallel, have less in common with real parallel turns than good wedge turns do. Even though you do not "need" to make wedge turns to learn to ski, you do need to learn to make the movements they require to learn to ski well. There is no shortcut, no way to "skip the wedge and go straight to parallel" that will overcome a physical disability that makes wedges impossible. You do not need to "learn wedge turns" before making parallel turns (because they are fundamentally the same thing--regardless of what some people believe)--but if you cannot make a wedge turn, then you cannot make a good parallel turn either.
I hope it works out for you, Acotiga. I would love to see some video of you--just walking around, as well as making various ski-specific movements (including actually skiing). Could you, for example, stand with each foot on a turntable (like a barstool) and turn your feet left and right, without turning your pelvis? If you can find a willing partner, you can do a simple test for range of leg rotation. Lie flat on your stomach, and bend one knee 90 degrees so that your lower leg points straight up. Have your partner kneel behind you (at your feet) and gently move your elevated foot left and right--which will rotate your femur--and measure how many degrees he can turn your leg in each direction before your pelvis starts to move. Measure and compare both legs. (I'm very curious how this test would turn out for you--feel free to post the results here!)
Good luck! Don't give up yet....