We'll respond shortly.
If you need to combine percentage and absolute sizes and you only need to target modern browsers, css calc is for you. Valid in IE9+
Yes! You can create batches of jobs, and then, JOIN them together before completing the parent job. At $500, well worth the price of the Pro license. See https://github.com/mperham/sidekiq/wiki#sidekiq-pro for more details.
I'm just a fan.