Normal build I use (not what I used to kill diablo):
450-500 resist all
825 life on hit
spiders swap to darts occasionally depending on what I'm fighting / if I'm grouping with anyone, grave injustice sometimes swaps to something else...
I swap my build around to often to say "this is what I use" but the above is the most efficient build I've used for what I would consider to be normal progression through inferno.
Note, I use horrify for the movement speed buff, in tight dungeons I often swap this out for wall of zombies with 60% movement reduction.
Mana - Yes our signature spells use mana, this was rarely ever an issue for me.
Pets - Useless past act 1 inferno.
VOQ/Zombie Bear build - Very feasible, used a similar variation with my own spin on it to drop Isatsu.
1.0.3 - Well, I'm glad there are achievement dates, because after 1.0.3 an inferno diablo kill likely wont mean nearly as much to me.
Did it suck? Well hell yes it sucked, it wasn't pleasant progression, it was frustrating and I died A LOT.