If u want to be a good CPA accountant u need good interpersonal skills, and if u cant be courteous then we cant help u, but since u copped enough trouble i'll give u a few tips.
If u havent done any accounting do 105, if u have, do 100, the difficulty difference between these two units is quite big (no GST in 105 last year). accg100 failure rate is around 30% and can get very tricky and tedious.
ACCG101 is an extension of 100, it can get quite difficult and the journal entries and "how to's" get very long. But if u applied yourself it shouldnt be a problem.
ISYS123 or COMP? choose ISYS123, one of the easiest subjects there is, havent even touched the textbook, just think HSC IPT, except they mark heaps easy. If u are an experienced excel, access and word user, it should be no problem. Enormous amount of content with a few *insert Frank Moisade's voice* IMPORTANT concepts.
Half of first year units for applied finance and accounting is number crunching and interpretation, whether it is crunching it like violet crumble or trying to digest some expired chocalate like accounting for shares and calls. The chocalate also loses its flavour in ACST101, where ur finger's go "pavlovian" on u when u see an annuity questions.
Make sme good friends at uni, sounds like u need some, u got a bit of anto-scoial behaviour there. It can be a great experience in life or can be a very lonely experience.