I've seen plenty of dSLRs in the past, though I haven't been for a couple of years.
There's no way you'd get a tripod in there on the public days.... even if they let you through (not going to happen), it's far too busy to actually use it safely. The place is manic.
Don't think there are any limitations with flashes in the main area, but they'll not be allowed in the arena or in the experience areas I suspect.