You wont be penalised for such type of redirect. You can block all the traffic coming from their domain or IP via .htaccess file.

Google wont penalize you for duplicate web design. But it does look at the layout of a web page to check how much content is above the fold using page layout algorithm. So while designing a layout make sure that you have considerable amount of contents above the fold. Web design doesn't effect ranking position directly but indirectly it can effect because of high bounce rate and other user metrics.

At the end of each blog post/article remind your readers to follow you on twitter. This work wonders. Another cool way is to pay by tweets. If you provide a downloadable resource on your website, then make it available only after tweeting about it. Make sure that your twitter button recommends to follow you, if a visitors is not already following you. With the passage of time you will get many followers.

such rankings drops are generally temporary. wait for few more days. How soon you will recover your rankings depends upon how frequently Google crawl and index your website.

Google can index URLs up to 2047 characters in length. You will receive a 414 error if you exceed 2047 character limit.

http://productforums.google.com/forum/#!category-topic/webmasters/crawling-indexing--ranking/h0aeO2_kpac