I am fine with that, @codinghorror worth updating the copy there.
This would introduce more work for moderators, if a feature like this would have to be default off.
Just cause you can solve a captcha does not make you a non-spammer. There is already a one-time hurdle, see:
Once you pass TL0 vast majority of the issues you raised are non existent. In fact, you passed TL0 on this very site already and can post all the links and images you want.
Rate limits will always be built in, otherwise a user can create an account and bot a forum out of existence extremely easily.
Sure, go for it if you wish:
It is the default selection in that dialog.
Disable all flagging though is never going to happen by default out of the box. If you want that you are going to have to customize your site.
We would if that was correct, but it is not correct, except in sites that have it enabled.
I completely agree that sites like https://discuss.reactjs.org/ that have this option on should do a better job at educating, but I doubt they even should have it enabled in the first place. Personally I hate when communities have "hold first post for moderation" enabled. It is user hostile and leaves a really bad taste.
I did, and wrote about it here:
We are not mailman, we are a different beast.
Anyway... this is a very long post and hard to respond to all of it, but the gist is that as a person running the forum you could customize pretty much everything you described here. You could start users at trust level three, disable flagging, allow people to post anything any time, reduce rate limits and so on. But ... as defaults ... they do not make sense.