As for each difficulty, I have a couple of concerns:
1: People entering at the last minute- makes it really awkward in regards to entries- there's no competition to try and make better and better runs for the contest.
2: Using previous replays where you can't confirm whether it was made for the contest.
3: What of people entering their replays for someone else i.e. if I went for a Lunatic LNN and sent someone a Hard LNN (Which I wouldn't, I lost 4 lives on stage 6 as Reisen on Easy cause I kept tabbing out) then technically you're claiming prizes twice, which you've already expressed is against the rules, yet you'd have no idea it was happening. There is no definitive way to define a run as one's own- do you know if there is anything we can do to prove what we are sending is legitimate?