After a winter cruise to the Bahamas I too am thinking of removing the staysail boom and staysail for my next trip down there. It's just too often in the way for storing the dinghy, for getting across the boat in front of the mast, for sitting on deck, etc. Furthermore, for the cruising I do, US east coast and Bahamas, I do not consider the staysail necessary. I used it but rarely and found it was only beneficial from a beat to a beam reach, anything further aft and it blanketed the jib. It was of course most useful when the wind piped up to over 25 but normally I'm in port in any winds higher than that. I can reef my 100% jib to 60-70% with no ill effects which should take me up to about 30 knots. If I was crossing any ocean or at least a major ocean passage the staysail would certainly be used and I would be happy to have it deployed.
As for the sheet angle I can't help you. I am sure someone on the forum has switched to roller furling and has it worked out. I've thought about just removing the boom and keeping the staysail but the sheeting angle to the staysail traveler would be all wrong. I've also thought about switching to roller furling but without a boom I can't see how to rig it given the need to run the sheets aft to the cockpit, installation of new winches, etc. In any case, I would consult a sailmaker but I bet he/she is going to tell you that you need to get a new staysail or have yours recut.
Good luck with your decision,
Don
'Surprise' 44 w/o