The problem is almost 90% of ICOs here are mere startups, they aren't companies or Organizations at all except for a few. Bitcointalk has more to offer them than they have to offer bitcointalk. To put things into perspective, there are forums which ask upwards of $1K for HYIPs to get their post pinned for a week, something which is a scam altogether. Imagine what bitcointalk is offering to these ICOs for free. They can create free threads run advertisements and all sort of good stuff without paying a penny to bitcointalk and since it's free for all, We see services like paid bumping get traction, You can't officially get your post pinned so the only way to get your post on the 1st page is by paying for bumping services.
I do agree with what you said in your DOs and DON'Ts but the problem is there is no one who will enforce these, nor do they have the budgets to hire experienced campaign managers. IMO, the first step should be to not allow these ICOs to run Signature campaigns for just their worthless tokens. This should reduce spam dramatically. As to reduce paid bumping many things have been proposed, from more rigorous moderating to new replies not bringing the threads to the 1st page. Each of them has its pros and cons which have been discussed countless times before. I still believe we need more moderating than what we currently have...