If you were serious about pumping something flat (bourbon, scotch, tequila, whatever), I would recommend using a CO2 powered double-diaphragm pump, like they use to pump soda syrup to bar guns or soda dispensers. They don't use a lot of CO2, and the liquid is never in contact with the gas so it doesn't have a chance to absorb it. Plus they work to always maintain pressure in the line so there's no need to maintain anything - just plug in the CO2 line and set your pressure once and the rest is on-demand booze, chilled, straight from the fridge.
I used this same technique when I had a bar gun, but I didn't want no stinking soda, so it pumped Gin, Vodka, Rum, Tequila, Scotch, OJ, Cranberry Juice, and whatever I wanted on the 8th button.
Back On Topic:
I see no reason why running the beer wouldn't work - I'm not sure what the line sizes are, but you could adjust pressures and hose length to accomodate. I think the plastic parts might get nasty after time and cleaning may be difficult.
-Kevin