Switch vs router and crossover etc... (S1 and iPad)

[Teej]

Networking is not my specialty, please help me figure some basic stuff out!

I already know that an Artist Mix plugged directly into my Macbook Pro with a cat5e x-over works. The Artist Mix works in tandem with my internet Wifi (usually tethering from my phone) so I don't have to switch between internet/controllers.

The plan: I have an S1 on the way and will eventually add an iPad to it as well. In the future I'd like to add a second S1 and possibly a Dock ... all with iPads at some point.

How do I do this?

Step 1: Single S1, x-over cat5e and done.
Step 2: S1 + iPad, Can I use the iPad with an ethernet connection with this set up? So I could get a switch instead of a router, keep everything wired and continue to use wifi only for internet connectivity.
Step 3: 2x S1 + 1x Dock + 3x iPad ... if the above is correct, I can get a switch at the beginning with enough ports for how much I want to expand and just plug-in as I aquire the gear.

Also, a couple basic networking questions:
For this application, can I connect a switch directly to my computer without a router? And if yes, should I be using normal cat5e or x-over cat5e between the computer and the switch, and between the switch and the devices.

Let me know if this makes sense or if I'm missing something. Thanks :)