Common sense dictates that a subdomain is likely to get some of the authority of the main domain due to its association with it, but obviously not all of the authority. At least this is my thinking on the issue.

I think this is a fine idea.

I think it's great because it will help users have a better idea of which sites are more relevant to what they are searching for.

there are lot of ways to recover from penality , remove bad links, give some quality links and then resubmit site.