You don't ever want to reuse your microfiber towels before cleaning them. Use the Microfiber Revitalizer if you have it, use LIQUID laundry soap if you don't (don't ever use powder), and either line dry or put them in the dryer with low or no heat and NO fabric softener in either the washer or dryer. No dryer sheets either. With proper care, they'll last years. I have some that are 10 years old at least!
I would say it depends on how dirty your vehicle was prior to the Waterless Wash. I've used Detail Spray after using it, but never the two you're planning to use. Honestly, I wouldn't because I just don't see how you can possibly get your ride as clean with WW as you do with a hose and bucket. And any leftover or missed dirt is possibly going to scratch.
Here's the thing with Leather Conditioner that most people using it for the first time don't realize. Once you've cleaned your seats well, you should apply the leather conditioner. I like to apply it with a microfiber towel or with my hands. Let it sit for a couple minutes, then wipe it down good with a clean microfiber towel. A LOT of times you'll see streaking or an uneven appearance after a few hours or the next day. It's normal. That's because your seats and leathers/vinyls, etc. are not equal in their dryness. The areas that are dryer will absorb the product quicker and look duller or streakier. The solution is as simple as reapplying. You may even need to do it three or four times until it's uniform. But once you get it all evened out , you should only need to do it once the next time. It's just a matter of getting it all equally treated and moisturized.