@Bainhardt
There is no feature at this time that notifies a reporter that action has been taken. The first step is a warning, disciplinary action, and then increasingly harsher punishments until the user has either lost all privileges on their account or they are permanently banned.
@Ixlone already keeps an eye out for alternate accounts and bans them when he finds them.
As for your other questions, they are certainly good ones and will most likely need answering at some point in the future. I don't have any answers for you at the moment. I suspect that we will start hammering out some sort of system if/when the forum moderator team grows.
The ultimate goal at this moment is to make both forums and comments a relatively pleasant place to be.
@Dysisa
You can certainly report spoilers. Please make sure that these comments are indeed spoilers and not speculation. I'd also like to caution you that it's unlikely that we'll ever really be able to stamp out spoilers but we'll do our level best to do so.
@Thoraxe41
You're nothing but shark bait!
@ninjadork
I'm not sure what you're getting at here. Everyone will be treated equally at MD. I don't favor one type of reports over another. If you're afraid that people will hide behind the rules, don't be. As I mentioned in an earlier post (I honestly can't remember how far back it was) the spirit of the rules are just as important as the letter of them. If someone is maliciously breaking the spirit of a rule, they'll not be able to hide from justice!
I have to be honest, I'm not very enthusiastic about the idea of an appeals system. It seems like so much work for so little return. Most people who troll and break rules on a regular basis have little interest in reforming and so an elaborate justice system seems like a giant waste of time. Perhaps my feelings on the matter will change, but not at the moment.
As far as shadowbanning goes, that's precisely what the block feature does, to an extent. It's your own personal shadowban! People will never know that you've blocked them, unless you tell them of course.
@alacaelum
There has been talk of an emoji-like system but no one wants to deal with upvotes and downvotes as they can very easily be abused.