Over-optimization, Duplication and Spamming Issues

Hi everyone, Living in Pakistan. I've some questions and need their solutions because I'm working 10+ websites comprising over-optimization, duplication and spamming issues.

1- I've a website of carpet cleaning before my joining this company some spammer SEO and link builders made so many bad links, duplicate links and also submit duplicate blogs/Articles. As a result we lost keywords ranking in Major search engines. Then I search all bad links by majestic tool and create a Google Disavow file and submit, but still ranking and traffic is going down. Now I don't know that what I do.

2- If we disavowed a domain e.g. "storify.com" because this domain contains bad links with duplicate content. Can we submit a new link with good content at this domain again? Google will consider it correct?

Waiting for kind Response