I'm thinking of doing the exact same thing. For the exact same reasons. So of course I think it's a great idea! :)

I measured all of my things-- sounds like a similar fleet of appliances to yours-- and I think 16" would work. I found nothing was deeper than 14" but was planning a shelf that's 18" just to have some wiggle room. Then I decided that I might just go ahead and put a countertop microwave in there so I went to regular counter depth.

If you show me your pantry layout I'd be happy to advise where to put things. But it's hard to say with no idea of your space.

Off hand and looking at my bread machine sitting on a 24" countertop, I can't imagine it or the crockpot on 16". I need room to take out the breadpan and shake it out, or keep a spoon or cup of liquid handy for the crockpot.

Another issue with using breadmaker and crockpot in place is that you don't want them tucked in, where venting steam will damage the shelf above.

With the exception of breadmaker, I plan to put all my small appliances in a base super susan. I'll still have to dig them out, but they should be easier to reach than in a deep cabinet.

I had our trim carpenter build-out our walk-in pantry, and it includes a table (based on a potting bench) that holds toaster, microwave and K cup machine. I wouldn't put my crock pot in there since it gets hot for a long period of time, and I like to vent the smells (so the dogs don't get too hungry!). Our coffeemaker is on the coffee station in the back hallway, so it's not in the pantry. I have two double outlets, one on each side. No outlet for the bottom shelf, since it's used for storing bulk items - mostly drinks. The table set up is nice for fixing sandwiches and unloading groceries, etc. No food is kept in the main kitchen area (only fridge). Opposite the table is a wall with deeper shelves for can goods, etc. The few small appliances that I don't use often are stored in the backside of the island. If I were to build again, I would make the pantry twice the size for more bulk storage and to store all small appliances.

If you want to have enough but not too much, I think it would be worth it to unpack or go to bed bath and beyond with a tape measure and notepad. 16" is fine, and 13-14" could even work. But maybe you only need a section to be that deep, with the rest shallower. If you have shelves that are deeper than needed then you'll be tempted to double park. Height would be more important to get right, to make best use of space.

While it might make sense conceptually to have an appliance shelf to display everything front and center so you'll make more yogurt and jerky, I think it makes more sense to place according to frequency of use. Stuff you would use only once a month (even if it were plugged in year-round on your kitchen counter) would go further from the door and on a lower shelf where you have to bend, or higher where you need to go on the tips of your toes. Save the prime real estate for things you use all the time, whether it's appliances, food, or something else.