I've been watching this thread hoping someone had addressed this.
I am a bit paranoid about this issue. I obsessively inspect the halyard, shackle, roller furler, etc., before hoisting the jib and mast and sailing. Having sailed larger boats all my life the absence of a forestay does make me nervous.
On the other hand, many small boats are set up this way. I've had my Bayraider for a little over 6 months and have sailed in 35 mph winds with no issue whatsoever. I think the weakest parts of the system will be the masthead block, mast cleat and head shackle. It looks to me like the jib luff wire and roller furler are plenty robust for the job and the masthead fitting would hold a truck. I'll probably replace my jib halyard every year - just to be safe. The thing that makes me feel pretty good about the system is that my body weight is adequate to position the mast. Tension is added to the system by raising the aft end of the jib boom but that tension shouldn't stress anything in the system to any level of significance - we are probably talking a couple of hundred pounds at rest.
I'm thinking about adding a deck fitting to which I can secure the halyard as a backup. A thought that has crossed my mind is drilling a 1/4-inch hole in the mast tabernacle and installing a shackle to which I can tie the jib halyard.
As I said, I'm paranoid about this. On the other hand, I've been a rock climber for 40 years and my paranoia has served me well. Never assume anything.
Has anyone else thought about this? Even if you haven't done anything I would be interested in your thoughts.
Ron