Thanks for your comment.
I agree that flagging can become dangerous in the wrong hands. We have seen even whales abusing the flag feature, so I don't think that reputation or age of account should be a specific factor for flagging capability.
There are many ways to prevent abuse (in general), however, most of them seem to require a "centralized" body. By allowing all users to flag, or not to flag, it encourages individuals to use their best judgement. Also, you must be aware that if you are flagging inappropriately, unless you're the biggest whale on Steemit and can fend off all of the other whales who might oppose you, The Community Can Punish Inappropriate Flaggers.
I have seen several cases where inappropriate flaggers were handled by groups of individuals who stood up for the victim of inappropriate flagging. WooHoo! The System Worked!
I have also seen cases of inappropriate flagging hurting helpless individuals with no recourse. *sigh * The System Failed.
Using flags decreases your Voting Power, so it's not an unlimited resource. I think this consideration was a very intelligent addition by the developers. It also means that no single individual can control all of the Spam.
Until there is a better system created, I think that encouraging the flagging of REAL SPAMMERS is the best thing that we can do. We need to all work together.