Slight white smoke probably was condensation....Regards to losing water...if it got too hot it would have seized....but this does ten to fook head gaskets...make sure oil has no traces of water in it...if its leaking out the block aslong as you keep water in not too much harm can be done!...Have a look for the leak on the back side of block exhaust side!

EDITED to say..the oil leak again unless pouring out aint a major worry aslong as you regualary check oil level!