With all due respect, I think these are very different situations. Compare:
- you must create 10 new posts
- you must scroll and read... stuff
The former is many, many orders of magnitude more onerous than the latter. Reading is completely easy and passive. Just scroll! Reading is fundamental on this and every other forum, just fall down the gravity well with us.
Forcing people to create posts is, pardon my French, really stupid. It encourages talking without listening, the worst kind of "post count" inflation nonsense, and posting is not even the core activity on a forum -- reading is!
I am not sure it makes sense to show a countdown timer like on an E-Z bake oven, but I am certainly for showing more just in time feedback when you attempt to do something that you are not allowed to do based on being a new trust level 0 (visitor) user.
Anyway, it's rare that a new user, who is just getting their footing and exploring the community, and isn't a spammer, would even need to do things like post more than one link, or an image.. remember that the new user levels are there for the new user's protection almost as much as the forum's protection.
I don't mind the idea of approving new user content manually, but I also think what you describe (you must post 10 things!) is a terrible, apocalyptic scenario, that can only end in tears. It would have me clawing for the walls in escape too.. just awful.