There are many Christians with better ideas about Christianity than Christ, and the same is probably true of Zoroaster and Mohammed, though I'm not aware of them.

There's a serious problem with this in Christianity in that you have to figure out what the founder actual said in the first place, which is very much an open problem concerning Christianity (and perhaps Bhuddism as well but I am less familiar with it at the moment).

For example, just this century with the rediscovery of the Gospel of Thomas you get a whole new set of information which is .. challenging to integrate to say the least, and also very interesting.

About half of the sayings are different (usually earlier, better) versions of stuff already in the synoptics, but there are some new gems - check out 22:

When you make the two into one, and when you make the inner like the outer and the outer like the inner, and the upper like the lower, and when you make male and female into a single one, so that the male will not be male nor the female be female, when you make eyes in place of an eye, a hand in place of a hand, a foot in place of a foot, an image in place of an image, then you will enter [the kingdom]

Or 108:

Whoever drinks from my mouth will become like me; I myself shall become that person, and the hidden things will be revealed to him