Okay, here is my 2 cents on both your questions...
1) Spinrite cannot be run on the 2200 itself. You need to pull the drives and run the spinrite on them attached to a PC. Hint: DO NOT boot the drives on a widows system (or any other operating system for that matter). Just connect them to the PC you are going to use and boot the spinrite, test them, then pull them. PERIOD! If you boot the PC with an OS (other than the quasi-OS spinrite uses), you will blow your drives "special" partiion(s).
2) Without more information, it is very very hard to tell, but my gut tells me you are having power supply problems. This is a common problem for those units. The power supply is probably getting old and now failing, even more so because of the heavier power draw drives installed.
3) I still say go with a Snap unit, except this time, a Guardian OS (GOS) unit. Many of those units can be had for decent prices used.
4) I have a 4400 with 4 x 500 GB drives in it (used) that works well. I also have some other units. If interested, contact me via email at
phoenix32x@hotmail.com or here in PM. Let me know what you want to spend, how much you need, and maybe we can come to something.
Hope one or all of those help...