Thank you for your question. This coupler uses the standard "Gas bladder" in the gas side so that it is used as a check valve. If you want to use this couple to fill the keg then you can replace the gas bladder with a standard beer line gasket.

Yes it can be removed with a pair of needle nose pliers but it's there to prevent backflow into the keg. This is a good feature to have to prevent contamination.

Do not remove it It is the check ball retainer.

That plastic piece is in every sankey it’s a tight-fitting triangular locking mechanism to keep the back flow preventing ball under it secure. It can be removed along with the ball under it but then there will be no back flow prevention.

If you have height constraints you can use an elbow adapter such as our low profile elbow bend (D1514). This will help adapt to a ball lock fitting without adding much extra height. From the floor to the very top of the coupler assembly on a Microstar 1/6bbl keg is 26 3/8". Cheers!