I think the main problem with your website was of duplicate content and Meta tags which were filled with too much keywords.
congratulation on your success.i think success does not come in a day.we have to wait for it and we need to give our 100 % effort for becoming successful.
Very detailed and helpful post. I think a lot of people have got stuck in 'SEO Paralysis' and are now to scared to take action incase it makes things worse. Great work on nailing it all out and moving your site forward and past a penalty. Recovering from a penalty might be one of the most valuable experiences you will ever have as an SEO.