To me, the "retouched" version looks like there is an unnatural level of detail. I do like the direction, but I'd back off the detail or midtone contrast a bit. It seems that every rock wall and tree has detail - and my eye finds it overly busy even on a computer monitor. Increasing size to 16x20 or so will make that detail even more apparent - and distracting.
It's a personal decision and will depend a bit on what paper you are using.
Definitely too much! If you're using LR4, keep in mind that the clarity slider has about double the strength it had before in LR3. A setting of 45 is what 90 used to be, and that's a lot for scenes like this. 20-25 is probably the most I would use for this shot. Stay away from the saturation slider and use vibrance instead; you'll be much less likely to push colors into the clipping range. Finally, use LR4's new softproofing feature to both see what an image will roughly look like when printed (assuming you have printer profiles installed) as well as creating a separate proof copy to which you can do mild edits to overcome a slight loss in contrast or color saturation. Again, that last item is best fixed with vibrance. Keep the saturation slider for graphic images rather than landscapes.