Penalties Don’t Impact Sites on Shared IPs
You don’t need to worry about your IP address in association with other sites that have been penalised, or spam sites
Reconsideration Requests Don’t Work for Algorithmic Penalties
Reconsideration requests can’t be made for algorithmic penalties like Panda and Penguin. You need to do is disavow the links, or fix the quality issues for the penalty to be lifted in time.
Only Manual Penalties Show in Search Console
Only manual Google penalties are shown in Webmaster Tools. They can be applied to a single subdomain, or all subdomains of a domain. They are removed automatically after a fixed period.
Monitor and Disavow Backlinks Regularly
It’s good to monitor your new backlinks links for potentially low quality, irrelevant links, and disavow them, to avoid any risks from backlink penalties.
Disavow Works Immediately to Prevent New Penalties
A disavow link submission file is processed as soon as you submit it, and the link will effectively be nofollowed or blocked the next time the the link is crawled, so this will prevent a new penalty.
PageRank Won’t Ever Be Shown Again
Visible PageRank values probably won’t ever be updated again, but they are still calculating behind the scenes.
Links from Sites Hit by Penalties Won’t Harm You
Links from sites hit by penalties won’t harm your rankings.
Backlink Disavow Doesn’t Do Anything Until Google Updates Penguin Data
If you have a Penguin penalty for backlinks, and you remove or disavow those backlinks, you won’t see any effect until Google updates the algorithm again and refreshes the data. John says it’s a long delay and you should go as far as possible with disavow including domain level disallow directive to make sure you cover as much as you can.