I've thought about doing the same thing several times, they can be a real pain in the ar5e sometimes (my kite even inverted once, so i'm not sure they're even that useful). Looking at them when the kite is flying directly overhead, it looks like they're not under load at all but I can't really tell during the turning. The fifth line also doesn't appear to rely on them at all either. Maybe give it a go with somebody around to give you a hand if things go pear shaped, then let us know how it goes