"Waiting 24 hours or more for the blockchain to sync..."
Wrong client. Try blockchain.info. Instant sync.
"You can purchase some bitcoins, which involves..."
Wrong method. Try BitInstant. Instant.
"Wait 50 minutes to get enough verified transactions..."
Could be a few seconds.
As a seller, you can choose the number of verifications you wait for. My web shop waits for the first only (fine for sub $100 purchases), so verification takes about 5 seconds.
If you wait for 10 verifications, well, yeah it's going to take a while, but you don't need that level of security unless you're buying a house.
"All of this would be completely impossible on a mobile device."