-Fuel filter is to the direct left of your finger (the golden 'circle' with the hose exiting towards your knuckles). Go to repco and ask for a fuel filter for an R33 GTST. Have fun replacing it, those hoses are an absolute bastard to get to and even more bastardly to get off.
-That thing above the fuel tank is the fuel tank lid surprisingly Guessing those lines are related to the fuel pump, sender and whatever else requires power inside the fuel tank. Probably a better idea to work around it as the last thing you want is your fuel pump dieing and having to tear all your sound equipment out to get to it.
-Doubt it would cause any visual damage to the top of the bonnet, more likely it will bend/ break the bov trumpet thing first.
-Behind the back seat, use the search function for tutorials on how to remove the backseat (its not fun)
-I left my skyline jacks (one from r32 which fit in the slot and the 33 one which came with the car) under a friends datsun a year ago and havent found another jack yet which fits in there, most are too long when retracted so probably best bet to find someone wrecking there R33 and buy theres