There are Access bypass methods you can enable, if you are able to implement one of those (which is pretty easy to do) you can do it.
Redirecting, unless you share the bypass tokens (which are static, problematic) is a no from my point of view. You could proxy those pages through the new project, but it wouldn’t be the same.
That’s just a normal rate limiting rule, so yes if you use a custom domain. You need to filter the paths correctly, but that’s just configuration.