As far as raising Longhorn cattle, I agree with what was said earlier about their disposition, hardiness, etc. But just like all cattle, there can be some crazy, hard to handle ones - these should be culled, as with any breed. Probably my favorite things about them are their beauty, and the calving ease of the heifers/cows.
The main difference I see in raising Longhron cattle is marketablility. There is a market for Longhorn cattle, but it is a niche market. Finding steady buyers can sometimes be a problem. Longhorns will probably be discounted at your local sale barn; therefore the best market for them is private treaty (out of the pasture).
A lot of people have pre-conceived notions about them, which simply aren't true. Such as, "the meat is as tough as leather", or "they will tear up all you fences". I have found neither of these to be the case, and actually, the meat was quite tasty. We fed a longhorn steer out last year, and really enjoyed the meat - very little fat, but still tender.
Don't really know about the skulls, as we have never sold any.