Using these on authority sites?

I have a couple of authority sites that cover broad niches like travel, health and..others. It would make a large hole in the pocket to cover every destination in this world for ex.
If it is an authority site, will google only de-index those pages or ban the whole site?
Or..If I put these on a subdomain would be better?

Any help would be appreciated.

Well i i think you can't really get authority Sites banned that easily. Since i dont think people in google are completely retarted so they would think some sites which have gained their authority would do blackhat or so you know what i mean.

But you can allways try. Tell them theres CP in their site that should get them off google lol

haha yea, I highly doubt a site like "digg.com" for example would get delisted for having their authors post a few cloaked pages here and there. I think it would be virtually impossible to get them delisted just based on the fact that the majority of the content that comes in IS legitimate, so if there were a few bad posts in the whole site, it wouldnt have much of an impact at all.