PS360+ multi-compatibility set-up: do's and don'ts? What to purchase (cables, etc.)?

Hey guys.

I'm looking to build a stick with multi-compatibility, specifically the following systems:

PS3
Xbox360
PC Windows
PS2
PSX
Original Xbox
Commodore Amiga
Sega Megadrive
Atari ST 520

Now, for Amiga/ST/Genesis I don't even need a PCB since I can just solder the wires directly on the contacts following a pinout and it'll be fine.

For everything else I decided to pick up a PS360+ after doing some research.

I got some questions for the techtalk wizards tho (been looking for answers for a couple of hours to no avail, also english isn't my first language which prolly made it worse):

1. Will it work out-of-the-box on PC Windows/PS3/Xbox360 just by connecting the systems to the USB port on the board itself through a regular USB cable? If not, what else is required to make it work on these 3 systems?
2. Will it work on PSX/PS2 by just connecting the board to the systems using this PSX to RJ45 cable (http://www.focusattack.com/6-foot-black-psx-ps2-to-rj45-cable/) or do I need something else in between?
3. What exactly does one need to make it work on the original Xbox? Is the Xbox compatibility even contemplated (should be but I didn't see a cable on the Akishop site)?
4. I've been told you can make it work on PC/PS3/Xbox360 also through the RJ45 port, what's the point tho, assuming there's direct compatibility through the USB port on the board? Couldn't you just use USB for PC/PS3/XBox360 and the RJ45 for everything else or are you limited on using only one of them for some reason?

Thanks in advice for your kind help, much appreciated.