thats okay, im happy to share knowledge with someone whos enthusiastic and persistent...
um so about the dALLAS thing, obviously im in no position to say for sure whether it will help you or not since I haven't been there myself. However, from what I hear, he's very condescending (and I've heard this from 3 different people myself) which couldn't be too good for your confidence. I've borrowed the materials from another person, and they didnt help as such but are useful in terms of familiarising yourself with the structure of the exam, so you know what to expect. In all, I say go to prep courses if u can afford it, but if not then just grab a trial exam from ur friend who goes and u should be fine.
Which section was hardest? Well, potentially section 3 could be the hardest cos you either get the shapes straight away or you don't. However, there IS a special tactic you can apply to succeed in section 3- if not for it then I woulda completely failed section 3. Section 1, as I've said earlier, is very difficult. ACER posted some sample questions up on their site but trust me, they pale in comparison to actual questions. So this section coudl also be the most difficult. However, I'm not going to say cos u should find out for yourself and work towards consolidating that section's marks.
What else can I say? Um u should worry alot about your UMAT, cos after all its worth 33pc. Apart from special coaching, what I CAN recommend is that you read up some books about logic and logic games. Familiarise yourself with the kind of questions they could ask you-there are not much (eg the syllogism) and you should be rite. After all, it's just application of common sense.
Section 2 is interpersonal relationships. Um this is a funny one cos all the smart ppl i know (high UAI) totally flunked this one, and im not making gross generalisations here. Again, just apply a little common sense and in fact, this section should be the easiest.