if you're going to tafe before uni its usually because you dont have the required uai to go straight in to uni (alternative entry). Keep in mind (stating the obvious here) that 1 year of tafe =/= 1 year of uni, and only 'some' course credits may be given.
don't want to spend 3 years doing something i hate
You're not really locked in, unless you do something special (combined/phb/honours etc). But most uni's have a very flexible first year. Plus if you hate your uni subjects that much, you will swap courses and sacrafice the years units. (i had a mate who went from comp sci, to arts. He was able to use some of his comp sci courses as electives, but essentially he lost a semesters worth of credits.).
At the end of the day - choosing subjects at uni with the possiblility of getting it wrong is a risk you have to take.