No
it's not a new thing that makes steem stronger it's just changing the name from flag to down vote BUT if you guys are going to do that please don't put the downvote button beside upvote button because a lot of people will click the wrong button like if someone wanna upvote he/she will click downvote by wrong and vice versa :)
peace.
They need to be placed on the same level and no warning, You can remove and change your vote many times.
it can be that you able to change it in a few minutes until it registered in the blockchain
but I don't think we need it
Very good suggestion.
even if you click flag now, you get the wawning that you are about to FLAG the post/comment and you need to confirm it...
so accidental downvotes wouldn't happen - unless your steemfriend just hates you for getting bigger rewards than he/she is.