Usually when there's a gas strut that holds the door it's to protect it from the awning arms, slide, or the orifice for a gas appliance. If the door doesn't impede any of these by being all the way open there's no harm in replacing it with some sort of holder.
The strut removes by pulling up on the metal tab on the end with a screwdriver. The tab is clipped to a pivot point mounted to the door, usually with screws so you can remove that too. If you do remember to seal the holes, I usually just put the screws back in.
Holders are cheap, get one from Amazon or eBay. I prefer the ones that have a clip on one end and a ball on the other. With those if you forget about it and try to close the door there's no risk in ripping the holder out of the wall.