You know, I read this and I think I might actually disagree with the comments above. I would increase the height if I were re-doing them (well, depending on where they strike you right now).
I agree that: 1) It will be costly. (2) It will put more stress on them, just due to the basic physics of leverage. (3) It will not be as nice looking.
However, it is safer. Go look at a Pacific Seacraft or a Valiant or other boats that are set up for real offshore work. They have higher lifelines that what most boats have. My problem with my lines is that they strike me right at the knees. Geezz! what a great way to flip over. Raising the lines would help. So what if you bent the thing! If it kept you on the boat, who cares if you had to replace it?? Maybe it just saved your life.
The only "counter" I will say to this is that most of the time in seas, you are really hunched over going down the Catwalk anyways... so it is not going to strike you like you were walking down the deck at anchor/docked. Still, every little but helps.
Just my thoughts.
PS I probably would not do this if it was just a lake boat or very coastal (not to say that you cannot drownd coastal or on a lake). Just, the seas will not be quite the same. If I did much offshore work at all (AT ALL) I would raise them. Also, make sure you are not going to screw up your Jib too much when you tack/Jibe.