3. Thinking of moving objects(my daughter), I set my camera to AI SERVO, turned off IS and snapped away. How would the focus on the 6D compare to this type of situation? I would hope it would be better? BTW, this was manually pressing the shutter button, not using burst.
5. Is using LR to clean up noise an acceptable practice? Does anybody really care if they like the picture? Most people that look at my photos(all but one really) don't even notice things like bad shadows, noise, sharpness, etc..
7. Again, the sharpness in my images are also improved in LR. And again, I ask, is it acceptable practice to use PP for things like this?
8. Without LR, I wouldn't be able to get the images I want. Sad but true. LR has allowed me to achieve the pictures I want.
9. I noticed someone mention the 6D will easily beat out the 7D in low light. Thinking about that, I like to take pictures without flash whenever I can. I like the natural lighting better. I think the 6D is much better for this scenario.
3. Likely worse. The 7D has more points and more cross type points with better spread. However, the 6D can be "tuned" for different types of action like the 5D3, this make make it a little better in some cases. I have yet to see a real world test between the two for tacking - mostly because that's hard to measure. However the 7D is a sports camera, the 6D is a landscape/portrait camera, so it's safe to bet the 7D will outperform in tracking.
5. 7. 8. In my opinion it is absolutely acceptable to process things like noise, sharpness, colour, exposure, local adjustments, ect. in LR - and you shouldn't feel "bad" about needing to do it. What matters is the final product. Think about it this way: when we had film you would chose your type of film to get different looks, use colour filters to change the colour balance, doge and burn to lighten up or darken parts of the image. There were even ways to change saturation, crop, do HDR, and much more. All the best photographers of the time did that. Ansel Adams did that. So don't feel like you can't use a bit of LR.
Another way to look at it: The jpeg engine applies contrast, sharpness, NR, tone curves, etc to your image. Why not take control of that process in LR? If you don't like the jpegs, that's not necessarily because you are bad, just that the jpeg engine don't produce look you want.
This doesn't mean take crappy pictures and try to save them LR, you should always strive to get the best exposures and lighting you can. However to argue that you shouldn't touch them after that is silly, just like it was in the days of film.
9. Yes the 6D will work better in low light, period. However I would recommend looking at off-camera lighting. A lot of people who say "I like the natural lighting better.", do so because they have only used the flash on their camera - and on-axis hard light almost always looks awful. However, put a flash in an umbrella off to the side, and you'll get great results.
The bottom line for you I think is this: The 6D will give you better IQ in low light and good light. However it may not track as well as the 7D. The 5D3 will do both very well, but will cost a lot more, and leave you without as much money for lenses. That's a really hard choice to make. I don't shoot enough action to make the 5D3 worth it for me, so I got the 6D and will get myself the 135mm f/2L (a sweet lens) with the extra money.
One way to decide is just to play with a 6D in a store. Bring someone to run around, and try taking pictures of them, if it does a good enough job, get it. If not, well you're stuck with the 7D or 5D3.