After the expiration of 90days, the forum moderators shall examine the performance of every newbie, then immediately award a certain number of merits(Let's say 10, 20, 50 etc) according to the performance of the newbie in this 90days orientation period.
All of the rest of your suggestion would never come to pass, but the above is the true deal-killer, since that's not what moderators do. \
Mods on bitcointalk basically put out fires, because there aren't enough of them to deal with all of the garbage posts and other rule violations that happen every day--if I understand it correctly, they basically rely on reports from members in order for them to see what's going wrong. And even if that's not entirely true, it's mostly true, and there's no way in hell Theymos is going to put the burden of monitoring all of the newbies on the forum (which increases daily) to make sure they're "progressing".
Besides, most of this has been suggested before anyway, well before you registered here. As was pointed out, Theymos isn't bringing back the newbie jail system. I also think the merit system is doing just fine, as long as merit sources keep doing their jobs and as long as non-merit sources keep meriting posts they like.