This is an excellent explanation thanks for sharing your knowledge! Would you say that creating new pages and reusing content from say the 'WordPress Hosting' page can have a negative effect on rankings?
My preference is HP, I find them really easy to work with although we do a mix of Dell/HP I would definitely do look more for HP deals than Dells.
iDrac is quite nice and has some more functionality though than ILO but ILO has better features for IPMI and gives me less hassle.
In terms of having multiple websites hosted in their own accounts, you're correct, but you can with many providers host multiple websites in one shared hosting account such as addon domains for cPanel etc.