Paypal is good for buyers on eBay; Bitcoin may not be.
right.
that why bitcoin is a perfect choice ... for food, supermarket ... and other face-to-face product (like in little market).
The transaction time is actually a hindrance to that.The transaction fee also makes it unattractive for small purchases, especially when conversion favours the local currency(like in my case).
No, it's not. Right now anyone can monitor the blockchain in real time using bitcoinj and listen for transactions, and within a few seconds can confirm a payment was made.
While it is true that that there is an ever-so-slight chance of a double spend attempt, it would need to be expertly choreographed and/or synchronized with finding a block to succeed, which makes Bitcoin perfect for small item sales because the double-spend effort would not be worth the return on investment. Double-spend attempts for large purchases can be easily mitigated by identifying the purchaser at the time of sale. Like for a car there is a title, registration and such. For a house and land, there is a deed and title transfer. Online purchases have a period of time between the order and shipping for the confirmation process... etc.