@Sproesser: It looks like you have most of your answers, but I will chime in on a few open items for you.
1. Can I connect a X5S camera and gimbal(made for inspire 2) to an Inspire 1?
I think you understand this is not possible
2. Will the X5S produce better quality RAW photo files than the X5R, besides resolution?(dynamic range, Low light sensitivity, background noise, color)
Here are the couple items to consider on this question. Resolution is obviously higher on the X5S - I think you already knew that. Dynamic range has stayed the same spec (12.8 stops) on both cameras. As for low light, background noise and color - because both cameras are using the same size sensor, putting more pixels on the sensor makes the pixels smaller. Smaller pixels generally do not collect as much light and are more likely to create noise - but in the
Inspire 2, DJI has introduced a whole new image processing engine and in theory could change image processing techniques easier as their technology improves. They should also have better noise control because of this. In general, as sensors have gotten newer and improved, their noise levels and low light capability has improved. Even with smaller pixels I think this favors the X5S. As for color, assuming you are capturing in RAW (DNG) your color bit depth should be excellent in both options.
3. Is the gimbal steady enough on the Inspire 1 pro for professional still photography? I like to be able to push shutter speed as long as possible.
Because you have asked about low light sensitivity and noise levels, I am guessing you will likely take images around dusk, twilight or at night. I think there is no doubt the
Inspire 2 holds its GPS position much better than an Inspire 1 does - and has far less vertical movement while hovering in place. This will help you if you push for longer exposures. Also, the
Inspire 2 has tripod mode. Its an extra slow stable mode you can activate and it will help you even further with precise hovering for long exposures. If you are only taking sunny daylight photos, either one can easily freeze actions and give a sharp crisp photo - but as you need more stability and longer exposures, the
Inspire 2 will perform better.
Here is another combo for you to consider. You could get the base
Inspire 2 (no extra video licenses) for $2999 and get the X5S without the DJI lens for $1399. This leaves you without a lens, but many people end up not using the DJI lens as much as some of the other lenses it supports so you could save an extra $500 and just buy the focal lengths you think you will need the most.
Hope thats helps get you all the answers you were looking for - and we, of course, stock all the items we have been chatting about. Let us know if you need any further help with this...
Michael
www.FloridaDroneSupply.com