The CC and Bosch use 304 SS. Close enough. Liebherr uses 430 SS. Which is a little darker and magnetic. 430 uses a "rolled-on" finish while 304 uses a "polished" finish. The grain looks a bit different. KitchenAid Micro built-ins usually use 304 and freestanding usually 430. It depends on which hood and wine fridge you buy what kind of SS it will have. Generally, more expensive appliance = 304 and cheaper appliance = 430. But there are exceptions. Liebherr is quite expensive compared to most fridges but cheaper than many built-ins.

"Clean steel" is a lower grade magnetic stainless that is then clear coated. The clear coat can be scratched off, and the stainless underneath can rust, especially if exposed to harsh cleaners. Actual stainless can also scratch, but as the metal itself is teh final finish, it can be buffed out if you really want to take the time and trouble. In appearance, the clean steel is more matte and a slightly yellower color than real stainless. Clean steel fridges also come with black sides and handles versus grey sides and stainless handles for the real stainless. That's the BIG appearance difference and sways most people to the real stainless.

I think you can definitely mix them. However, I wouldn't mix them on the same wall. For example, if your fridge and your range are on one wall in black stainless, you could add a regular stainless DW and microwave in the island. If you're going this route, carry the mixed metal idea through to your faucets, hardware, and lighting, too. Lots of great photos on this site with mixed metal finishes in kitchens. All that said, I wouldn't do this if you're planning to sell the house in a few years. If it's a look you love and you will be in your home for many years to come, go for it.

Both work equally well on an induction cooktop. I use my carbon steel more than my stainless. The carbon steel is more like cast iron except lighter weight and it heats faster and a bit more evenly. Enameled cast iron is also another good choice for sauces that are more acidic or contain a bit more sugar.