On Clean Server 2003 Install, Windows Cannot Find Any Drives

Yeah, it sounds like 0 and 1 are RAID 1 (mirror) and 2 and 3 are also RAID 1. As for disk 4, take a look here. That is the manual for your 2850 and shows you what all the various blinking scenarios on the disks mean.

You mention you don't see the second RAID set in Windows. Are you just looking at Windows Explorer? If yes, that's normal. You need to launch Server Manager, navigate to Disk Management and there you should see the 146GB drive. Right-click it to initialize and format the disk and assign it a letter. Once it finishes formatting, you'll see it in Explorer just like the 73GB mirror.

ESXi on fully supported hardware from any of the major vendors will generate RAID controller alerts visible in the VI CLient. Since the H700 on the HCL I'd be very surprised if it didn't provide alerts, the older PERC6 cards definitely do, sometimes to the point of being annoying. It would be nice if VMware (or anyone else) would provide a definitive list of what level of fault reporting their built in hardware health monitoring can actually provide for each device but that's not something I've ever been able to find.

This would be a lot easier to figure out if ESXi supported SNMP but it doesn't unfortunately, you have to use WBEM\CIM which is not quite as easy to enable and interact with. The Nagios\Python script referenced in my answer to this related question might give you some better information if you can get it working.

Dell have a reasonably useful document here on the various steps you can take to enable more advanced monitoring through the Open Manage Server Administrator agent on ESX & ESXi V4\4.1 that you can work through if you want to fully enable remote monitoring on your ESXi hosts. Even with this you are limited to CIM\WBEM and SNMP traps, SNMP queries don't work on ESXi.