[Branda] Benifits of WPMU DEV

As a digital marketer I have used this product for a couple of days. I want to recommend to our company to use it continuously. There are some question we are concern.
1. Is WPMU all in one for optimzing of a website? like SEO, Images optimizing and so on?
2. We have three websites, two for landing pages and one website is in redesigning and building, do you offer discount if we use WPMU for each website? or can I have one plan to cover these websites.
thank you so much.