Yes, you can. But the whole idea of the shadowbanning is that the one who is shadowbanned does not. So you get this effect where someone is talking to himself or the walls and they don't even know it, sometimes this goes on for years.

Thank god I know I'm shadow-banned.

Not related to showdead, but one can also get shadow banned from being able to up- and downvote here.

There's no second level I know of unless we consider automatically collapsed comments to be a second level.

You only have the "show dead" option on your profile when you have a certain amount of karma IIRC

No, you have it always.