[Suicide Junkie]

C-14 dating (and every other form of radiometric dating) relies on two unproven, untestable assumptions: 1) The naturally occuring ratio of the radioactive element to the resulting element(s) has always been the same as it is now; 2) The rate of decay has always been the same as it is now.

1) It dosen't have to be exacly the same, and it did vary by a little. See the link below.
2) is quite reliable if not technically provable.

Check out:
http://www.rlaha.ox.ac.uk/orau/01_04.htm
and the bit on "How radiocarbon calibration works"

First, it's not taught as a "best guess," but rather as fact. Open any high-school, middle-school, or elementary science textbook and read the first paragraph: "Billions of years ago,..." The entire Eohippus series is still included, even though Eohippus is now thought to be a type of badger probably still alive in Africa (the daman), not to mention that it's been found right alongside Equus. Even embryonic recapitulation is frequently taught.

Well, I'm not sure where you got your textbooks, but I'm not seeing what you're seeing.
Embryos for animals do tend to look alike, naturally. A head, body, usually four appendages, a tail. Start with a cell, then a ball of cells, then form up some basic parts, heck yeah they look similar for the first while.

Nothing like "human gills" or stupid stuff like that. Sounds like something a mean older brother might scare his little bro with.

Not sure what you're getting at with the Eohippus thing...
Corrections, if shown to be nessesary, are a part of science, and in any case, texts tend to lag behind (as they require writing) not to mention schools need to buy new books on thin budgets.
Of course, the first google hit on the two gives:
http://www.talkorigins.org/faqs/hors...pus_hyrax.html
The evidence does lead to billions of years...

Second, evolutionists operate under the assumption that evolution is true.

And creationists?

If the weight of evidence points towards something, and using it gives results why would you not use it?
If evidence builds up against the current theories, then a better one will be developed.