1. Yes definately. You introduce the basics like Demand & Supply in 1/2, but you go over it all again in 3/4. I know afew who picked it up in 3/4 and found it very managable.
2. Obviously some people will and some people won't be interested by economics. But I definately found it interesting, and certainly one of the more relevant and practical subjects in VCE. You can actually draw parallels with the real world even with your very basic VCE knowledge.
3. Again, difficulty will differ person to person depending on their skills and abilities. However, I personally think it's one of the lower demanding subjects in terms of homework and study. Establishing the concepts in class is very important, and theres afew definitions that you really have to know off the top of your head. Basically you've just got to get familiar with applying them to questions, which is the harder part. Knowing how to structure an answer was probably my biggest challenge in the exam. So... I guess maybe 5-6/10ish?
Anyway hope this helped abit. I quite enjoyed VCE economics, hope you do too.
EDIT: May have overstated the difficulty abit.