you are raising a valid points.
Self voting should not be allow it's just like self praising. If it's not possible it should be restricted to a very little amount like $0.05 so no one felt it interesting.
Bots are not doing any good for community. steemit is not only about earning reward but it's all about sharing ideas of different brain.
Short comments: It's difficult to judge about short comments. however short comments like good job, nice, well done should not get any upvote.
Contest is not a bad thing at all. It's a better to restric post per day. No one is allowed to post more than 3 post in a day. it will help in a better way.
nice post. keep sharing @asolopreneur