Tell you're client that you're putting your website at risk if you want this kind of strategy. Quality is what Google is after - and spam is what it's against. 30-40 backlinks a day can be really spammy especially if you do not have a wide range of resource.
Quality link building and connections through online communities. These two are the biggest factors affecting a website's keyword raking status. Quality backlinks should have unique and timely content and your social media should have a lot of interaction in it like the number of followers and links, shares, comments, retweets and mentions.
I emphasize on content focused Press release, article submissions, blog articles; are they help in improving the site rank?
Your SEO strategies are mostly fine but if I were you, I would stop submitting content to article submission sites. They tend to be sometimes spammy and has duplicate content. Focus more on creating online interactions like in social media, forums and even blog commenting.