when phase 2 arrives (november 10-12th), you are entitled to make the main payment. if you don't do it, aliexpress will return you the money (reserve) you paid in phase 1. so you can't cancel it now, but you'll get back the small quantity you paid in the pre-order.
about audio & video store.
i've received a cable and audbos p4, both in perfect condition and on time.
and now, i got dm6 refund; paypal refund, at last, cancelled ali dispute, confirmed item reception, agreed paypal amount to cover paypal fees, and he honored his word. 182.50 USD transferred, -10.16 USD fee (commercial transaction), got 172.34 USD, which is what i paid for dm6, approximately. no problem for me, i'm ok and seller has been communicative.
so the main problem with this order was his distributor couldn't serve the product in time, and the seller wasn't able to ship any package. this is not so unusual nor grave in chinese business. let's hope they can receive the product before 11.11, to full fill the pre-orders.
it's true that is a tricky seller. i mean, he gets orders while having no stock without any advise, lies or use false excuses when can't ship the order, sometimes chooses weird shipping carriers, don't agree on disputes and demands for paypal refund (if you accept this path, remember that paypal will take 4.4% + ~$2 fees; seller will agree in accepting this).. there are many ali sellers which show this behavior or similar, like the banned ones. but they often offer the best (cheapest) deals. there are others, like niceHCK, which often offer very good offers and customer support overall is quite better and nearer to what we are used to.
you choose if you don't mind taking the risk of getting some headache and wasting time, when price difference is noticeable. if there is not much difference, better go for a very reputable shop.
at the end, you learn to deal with this way to make business (so far than our westeros costumes), and the result is satisfactory in most cases.
EDIT:
sellers can't make any business with your money, because they don't get paid till you confirm the reception of the goods.