oil 'sammich' plate
your leak, sounds to me like the belt-side crank seal -- i have the same so i get lots of 'oil wetness' around that section yet you can't see where it's really coming from. best bet is to remove the cam belt cover (which can be tedious since you need the pulley off) then take a look behind the scenes..
as for your oil pressure gauge not giving readings straight away, that's pretty normal. think of it this way; when you have a long pipe plugged in to a tap, even though you turn the pressure up or shut the tap off, the response on the other end of the pipe is never instant right..? same thing here, the oil pressure emanating from the flow difference at the pump all the way through the galleries to the sensor takes a few moments -- nothing to worry about at all.
i'd say, watch if for a couple more days then report back if you are still having massive problems with it..
happy motoring..