Thanks everyone for the feedback!
A couple comments:
1. We did weekend updates the first year and that was pretty rough for us as a small team, so we generally try to run the event just on weekdays. This includes the daily challenge question. It obviously does not include responding to forum questions

2. E-mail confirmations/entry confirmation: There were a couple ways to accidentally get multiple confirmation e-mails, but this doesn't show up as multiple entries in the system. The system we're using is pretty smart, so really the only way you could end up with multiple entries is if you are intentionally gaming the system with multiple sets of information. If you're unsure whether your entry went through, you can clear cookies and try again with the same e-mail. Also, if you see the "get daily entry" button, it means you can get an entry for that day. Going to the page from a device without the cookie and filling out the form again will yield the same result.
Also, the entry confirmation is a new thing for us this year, so there is certainly some streamlining we can do for future events.