Stoodoo, the temp and pressure you state seem about right for the carb level you are after.
I have a couple of questions:
1. How did you initially carbonate it?
2. Were you previously using another tap with no problems, or is this a completely new system?
3. Is the tap mounted straight through the door or in a font?
I agree with the others who have said it sounds like your keg is over-carbonated.
It's worth mentioning though, that if the beer in the last bit of line can warm up, that will often cause foaming problems. Try and insulate the tap from the fridge as much as possible (eg, use rubber washers) - otherwise the cold beer is being warmed by the thermal mass of the tap itself AND the fridge exterior. If you can insulate it then the cold beer only has to try and chill the tap on its way through. Another way to look at this is that if you have good thermal conductivity between the interior of the fridge and the exterior, then the poor old fridge has to work harder as it is trying to chill the exterior panel of the fridge and the air around that too. This way there will always be a larger temp gradient than if the tap is isolated.
Draught systems are a very zen experience, there is no substitute for time to let everything equalise. The basic idea of a balanced system is to sort out your temperature first, then your carbonation levels (ie pressure), then tweak the resistance in the lines to regulate the pour to a comfortable speed. If you don't have adjustable restrictors, the easiest way to do this is to start off with lines that are too long, then shorten them a bit at a time to increase the flow rate until you are happy.
In my converted chest freezer I use about a metre of 4mm ID beer line (it's a prick to get onto QD barbs but it can be done - and the thinner line gives a nice even resistance). I tend to just run a 'house' pressure of ~80kpa (~12psi) at ~5C, and I get a perfect pour with no foaming - and that's just with old swing-top pub taps, nothing special. FWIW, my taps are level with the tops of the kegs.
I generally force carb after kegging at about 300kpa (22psi) and rock for about 30sec, just to get a tiny bit of sparkle into the beer so I can try it immediately. Then I vent the excess pressure, hook up the lines and let it gently come up to full carbonation itself, it takes probably 3 days or so to do this. It doesn't stop me drinking it in the meantime, but I try to stick to the beers that have already balanced.
(edit: tidy up)
