1 Brand - 2 Domains question

Hi folks,
I have a question regarding a brand and google. I started a brand in a niche 6 years ago (a brand with a .de--> Domain A). After struggling pinguin and manual penalty the domain has half of his traffic. Manual remove all backlinks would be too much work cause it was optimized the "old" way. Then I started 1 year ago a second one named a brand with .org (Domain B) with complete unique content, different images, site infrastructure, theme, hosting, IP. Gave this domain 30 links until know, some are very good.

First question: Can this domain rank for the same terms as domain A or is google going to say that this is the same brand and will not rank both? Is it better to forget this domain 2 in order to start over with a total clean and other brand (domain C), lets say domain new.com ending? If I search for "brand" in google the older one comes of course. Until now domain B ranks with subpages but not with homepage. Takes it a while or will it never rank with homepage?

Perhaps anyone has experience with it and can share it.

Second question: Let's say I will start over with a total new and another brand, I would switch the already build links from domain B to the new one very slowly. Would this be ok? Is here any advice for that? Or just pick good links from domain A and switch to domain C?

Nobody here with similiar experience about this?

I don't have experience for this, but as long as you do not have duplicate content on Domain B from Domain A, Google will not recognise it as the same brand and rank it lower (think of Wordpress.com and Wordpress.org). If you don't plan on using Domain A, the neither 301 redirect it to the new domain (if the pages are the same) or abandon it completely if it isn't generating any traffic.