what about collective creations, when more than one person creates the same artwork? this should be ok, right?
I don't really see any issues here.
As long as the artwork is original and is composed or conceptualize by you and your colleagues -- that's fine. However, you will be the one responsible distributing the rewards among your friends since they are involved who put an effort in making the artwork materialize.
Just don't commit plagiarism/artwork stealing -- there is nothing to worry about. Goodluck.
Yeah the rules of the artwork also states the same that you could present any type of artwork like hand drawn or digital and you can showcase the collective creations also but two could not be identical at all as we all have different ideas while making these arts.So try to be original although you can have an idea from previous contest but make sure it's your original idea.
Yes it's good that you can submit your friends/family members entries aslo and if you win you can reward them for their contribution that has helped you to win but would say also write up in your submission giving them credits about the same.