I personally wouldn't shorten a good hose. One that had a leak, sure thing, but to shorten a perfectly good hose would be a waste in my opinion.
If you only want a 10'-20' hose just make one. You can buy hose material and brass fittings at your local home hardware store. Use ALL stainless steel hose clamps.
Another option is to just buy a shorter cheap air hose from harbor freight. I've used regular air hoses connected to a pancake compressor and the second stage of a regulator for many many years to clean the bottoms of boats, underwater maintenance, etc.
I don't know what hooka setup you are using, so I don't know exactly what hose connectors you have, but if safety is your only concern, I don't see any problems with shortening a hose.
I had the same problem I coiled up 30 feet of hose and valcroed it so it will not slip when you pull the hookah.
I have the coil floating in the water to help cool the air.The longer hose holds a breath of air if you need it.
Think twice or more about using hardware store parts to make a hookah hose. It is not safe to breathe some of the crap they use in making them. Coil it as suggested or contact any of the hookah manufacturers. They can sell you a shorter hose.