Thanks guys! 
Will it be hard to do it without 1&2?
Most of the stuff i learned in 1/2 wasnt even relevant to 3/4 so you'll be fine especially if you are passionate about english.
Is there at least one or two topics that I should read over though?
I'm in the exact boat as you and am doing EL via Distance Ed next year as well.

And I've been there, done that with the asking of every single Year 12 EL student I've met about the course so, here's what I know that might help. ^^
In answer to your question, reliable sources have told me that mastering and grasping the knowledge the 5 subsystems of language is paramount, so perhaps read over that in-depthly (not a word, I know but can't think of anything else now:p).
Units 1&2 are different in content to Units 3&4, so don't worry too much about what's been covered, except those subsystems. Obviously, if you have the time or unction to, you can read through the Units 1&2 texts; though I personally won't be doing that.
If your going with DECV, you'll realise they use the Heinemann text. Apparently while this is a good book, it'd be more advantageous to you to get your hands on Living Lingo by the VATE, and have a good look through that and use it as a fallback supplement.
Derrick Ha and Hannah Gould are also people who you might want to try getting resources from. DHA is apparently rather brilliant, so says stonecold, and I'd trust him, lol.
If I've left anything out, you can just ask again; sorry I can't think of anything else at the moment. :S
Oh, and in regards to the MUES Criminal Justice Studies, my mate came about an inch away from concretely deciding on it, and then changed her mind. Apparently she just didn't have the passion for it that an Enhancement student required, and I agree. Unless you find the affiliated 3/4 or 1/2 subject remarkably fascinating, don't do it as it simply be a hassle. But if you really liked Legal, which is the prerequisite anyways, go for it.
I'm applying for MUES Biology, because I truly love Biol as a subject and the Enhancement Program from all I've heard, really is rather brilliant. ^^
History in the opinion of the smartest Yr 12 kid this year, is not worth the trouble, lest you have a flair for humanities. If you're more maths/science based, I'd say go for EL anyday.

If in the end you really couldn't decide, couldn't you drop English and replace that EL, and do the Enhancement as well?
Hope that helped somewhat,
