I have some thoughts, but no real suggestions.
On growing vs. buying your nug: It saddens me that a person who grew their own nug can lose to a person that has never grown even an onion simply because that person happens to both live near and have access to a dispensary (and have the money to
buy a nice-looking bud). Yes, we have a plant of the month contest, but it is a fact that there have been plants that were in no way standouts - which still had some nice buds. Unfortunately, I don't know any real way to guarantee that entrants would all be home-grown (even if everyone agreed with me).
On submitting the same nug/plant photo in multiple
contests: My problem with this is that, well, does the member still
have that nug/plant? Plants get harvested, buds get toked, yet pictures rarely go up in smoke.
Odin gave a good example of another contest, and in that case it is much less of an issue - but people tend to keep their vehicles for (relatively) longer periods of time and use them every day; once you use your bud, it's just a memory. If a member wishes to submit a plant this month, and submit the same plant next month (and it is still alive and growing), that would be a different story; as would submitting the same nug twice if the member still possesses it. The difficulty, IMO, is in knowing if the member still has the nug/plant or if he/she only has the picture.
On working your ass off: We all know that both you and
Soniq420 (and the rest of the staff) do a lot around here. When someone is unavailable and you cover for them, you are not trading your workload for his - you are
adding his duties to your pile. Allowances must be made for the human factor. Besides, you're doing a pretty good job of it, lol, and Soniq probably appreciates it even more than we do.
On bringing back the member of the month contest: I for one appreciate it. It was a great way to show my appreciation for members who went that extra step in trying to help others. Not everyone's circumstances allow them to grow (or buy) a choice nug or plant, and not all of those who do feel comfortable enough to post pictures. But almost anyone can help others, whether it's by sharing their knowledge, helping members use the site properly, finding others' answers to members' questions... or even by making us laugh - or think. It is a contest that anyone can win, even a fairly new member (even I won it once). And it is a contest that the "entrants" do not enter themselves in but, rather, are nominated by others who feel that they deserve the chance to win. It gives us a chance to recognize good in others - and to thank them for sharing it with us.
On changing
contests, their formats, and changing/adding/removing rules: It is your site and obviously you can do what you wish to do. I greatly appreciate the fact that you allow us to voice our opinions and consider our input when you make decisions. But might I respectfully suggest that in the future you either wait to make changes until a contest is over (even if it means that there will be a delay between
contests) or that any changes that are made apply only to future
contests and not ongoing ones?
everyone
I'll catch up on this more later there's a lot of reading! 
Oh and TorturedSoul, it just give's us something to aim for, you can't tell me the nugs are better manhandeled all the way to there and back... Janja's got my attention with Purple Mr. Nice that's some fine stuff right there buudday can't wait to try mine out!
But that's funny MountainHigh, and i'm with molotov, but there needs to be a limit of posting the same picture, I personaly don't wanna stare at the same nug a whole year! Maybe limit to reposting it no more than once more, the time they do is up to that person. Any thoughts? 
N I feel ya man.