Well said, it's a real shame that the possibility of tickets being cancelled kind of puts a damper on the excitement of getting tickets, especially considering most people are not intentionally doing any wrong and are just confused by weird wording and rules by u2.com. The presale thing is fantastic, it just needs a little tweaking to get rid of the confusion.
I myself am kind of scared to use any codes now because the code where I used up all 4 ticket allocations is still seemingly valid yet my other one (2 tickets) is not. What makes it harder is the fact that they don't have a way for you to identify what code has been used and how. Anyway I don't like to complain much, I'm just grateful I was able to secure some tickets