Yes, it does cover laptops; the warranty I purchased was for a small laptop/netbook. Also note that you can purchase a Square Trade warranty on almost any product for up to 30 days after the purchase (but please check their fine print to confirm that).
Linus, that's a great question to ask. You may want to check Squaretrades Terms and Conditions for they may have an AU one also. I cannot speak for Squaretrade myself because i have no affliation with them. Hope this helps!
I am not familiar with apple coverage. I do know this coverage offers coverage for drops, spills, etc. I had problems with my laptop and they offered either to send it in or take it to a local dealer and they would pay me the cost up to $149 (the cost of the warranty) and they would refund me within 2 days via paypal or credit card. I chose to take it to a dealer and was refunded the next day via paypal. this was faster than sending it in - no questions asked, sorry i couldn't help you.
Not sure about some of your questions, but it did cover a new memory module for me that was not covered under Apple Care since it was added after market, but I could show that it was installed when I bought my computer and bought my Square Trade protection plan. I bought a new memory stick, sent a picture of an invoice to Square Trade and they sent me a check very quickly. I installed it myself, otherwise they also would have paid to have it installed if needed.
I don't think so, but just make sure you keep your receipt as they will ask for proof of purchase for your laptop before they perform any repairs/replacements. I would double check though on their website.
Yes it does, if you go to squaretrade.com you'll be able to see all of their options.
I would contact the company first however, just to ensure you don't end up purchasing the wrong plan, or try to cover something they won't cover.