Question is - how complex is the whole rack set up deal?
It can be as complicated or as simple as you want to make it :) The E530 looks fairly straightforward, no MIDI to deal with so it's not going to be much different to having the Screamer head in terms of complexity.
Do you need a dedicated power supply?
No - both Feline & I happen to use a Samson PS10 power conditioner but it's not a requirement. I have it for convenience, tidiness & portability - all the devices in my setup are powered from the PS10 so I can leave them permanently connected in the rack & just have one power cable trailing across the floor. If I take the setup anywhere I just wind up the power cable, put the lids on the rack case & it's ready to go - no need to carry a box full of cables or completely disassemble whenever I want to move it). You could just as easily carry a bog standard multi-socket & as many IEC leads (aka "kettle" leads) as you need for all the devices.
The E530 manual mentions shielded stereo cables and all sorts of connections and that which is a bit confusing as i'm clueless about this at the moment...any rack knowlegde appreciated!
Not half as complicated as it makes out: All the connections are standard ¼" mono jacks (same as a standard guitar cable). The bare minimum you need is a lead to go from guitar to preamp & another one to go from the preamp output into a power amp (or other device). If you want to use the FX Loop you need a few more. Don't worry about the "shielded" bit - any decent quality cable in the appropriate length will do. You don't
need to run it as a stereo setup, it will work just as well as a mono preamp - it's only really useful if you are using a stereo FX processor & wanted to take advantage of "panning" effects, or are such a megastar that you needed two poweramps to run that wall of 4x12s :)
Had a quick skim of the E530s manual & I'm guessing that you'd use the freq. compensated output(s) to run into the PC or a headphone amp (assuming you didn't use the built in headphone amp) & the standard Line Out jack(s) to run into a power amp. I'm guessing that the freq. compensated outputs have some sort of cabinet emulation built in so it doesn't sound like a wasp in a jar when recorded direct...