The optimum/best settings for publishing projects

Personally, I think you may be asking for the moon here.

There IS no single set of publishing settings that will guarantee your projects work across all devices, OSs and browsers. If it were possible to do that, this forum would be a lot quieter.

You have to look at your specific target audience makeup and choose settings (after exhaustive testing) that work for that segment.  Sometimes you end up finding that you really need more than one version of your content to accommodate different segments that have vastly different requirements. 

Welcome to the wild world of e-learning in the mobile era!