Off ye old top of me pate:

In FFC Blackmoor, elves were tech savy - hence the fire hoses thing.

Wesely played a "half-Elf" a few times and he told me that elves were freely sexually promiscuous in nature, but looked down on cross species offspring. Any Half elf born would be immediately given to the non elven parent to raise.

Wesely also related a story where the object of the adventure was to rescue an elven princess name "Lotsa" from Blackmoor dungeon. The reward for doing so was Lotsa's hand in "marraige" for one day.

Also there's a fair amount of info on elves in Arnesons "izmer" write up.