Hi Ashley,

After days and days of reading, I, too, switched to gritty mix just a couple of months ago, and switched over almost all of my houseplants. All but one are doing wonderfully -- and that one hated me anyway and intent on committing suicide.

So I will answer what I can.

1. Someone else who has planted these can address, :-)
2. Depends on the plant and condition of the roots. For the majority, in all repotting (regardless of mix), I untangle the roots and give it a trim. I'm pretty ruthless about it unless I've grown it from seed. If the rootball is a madhouse with tangled roots, then I chop off the bottom 1/3 or so and THEN untangle with my fingers, shake off as much soil as I can and dunk in water to get remainder. (Repotting into regular potting soil, I didn't do the last part.) objective is to remove as much soil as is possible before getting into GM, and trigger roots to grow faster.
3. I waited 2 weeks to begin a very mild fertilizing solution.
4. Yes and no -- see #2. :-)
5. You CAN, which isn't the same as you should or must. By the time you root prune, you may even be able to use a smaller pot. As a general guideline, I'd recommend keeping it in a similarly sized pot or one step up in the new mix. Making a lot of GM to fill a large pot when not necessary is...unnecessary, lol.
6. I use both and indoors, it makes no difference, it seems. Go with what you like. Outdoors, I like clay pots but solely because it doesn't get as hot and "breathes" but I have plenty of plastic out there, too.
7. Some people wet the mix before planting to soak the Turface and especially the bark. If so -- I'd leave it in an open container until dried to the bottom. If not wet, I'd put it into a Tupperware type of bin -- size depending on how much you have left.
8. Yes. What humidity the plant needs to thrive doesn't change on account of the mix. Just think of it as "provided that the plant gets all it needs, GM is the ideal medium in which to grow". This would definitely include humidity, light, etc.
9. Can't comment on that.....
10. Any repotted plant needs some TLC -- more frequent watering, less stress. If you already have dim light, *I* would not be too worried about it. I mean, for most plants, it is neither necessary or warranted to put it in a dark room to recover.
11. Depends on entirely on the plant and when its best time is. Ideally, you want to do all this when the plant is most robust and growing -- like doing surgery on a healthy vs. not so healthy person. But me, personally, I repot whenever I feel like it, haha. The plants make it, but it's not what is recommended and if you are new to containers -- then doing it when the plant is strongest and busting out new growth in your zone is probably best. That said, while I don't know about your orchids -- you do want to make sure you won't kill your peace lily between now and then by overwatering!

Hope that helps. Someone with much more knowledge about this mix will surely come along to give you more advice! :-) Have fun repotting!