Well, don't Heroes "risk it" in every battle? The point of this is that it's a (nigh)Certain-to-Die choice. If the odds don't massively reflect that .. it makes it pointless. If the higher chance is simply you get wounded I can see more people lamenting how their Heroes spend more time Wounded and unplayable instead of dying off when they want them to.
The chances of getting killed in any given battle are very, very small. Well under 1%, I would say.
Yay for a single Fame point? I think we can afford the one-up on Fame. It can't exactly be exploited that much. No more exploitable than someone making an adventurer just so they, or someone else, can execute them.
Four fame points: one for regular hero death, three for legendary.
That's enough to tempt almost anyone who cares at all about fame into, ah, indiscretions.