Adding Structured Snippet, Meta tags, and opengraph data to iMIS

Hello,

I am a digital marketer and SEO specialist for my company and we are unable to run the most recent version of iMIS RiSE platform due to a variety of reasons but I still need to add requisite information to the headers of individual pages as well as tags to the pages themselves to comply with industry standards. This provides a few questions/challenges:

How do I create rel canonical and other metatags in page headers?
How do I add schema.org JSON scripting to add structured data and open-graphs?
Is there a way to edit headers beyond the template?
Do I have to go through and hard code the scripting and open-graphs to the various pages?

I would like to just focus on these despite further questions. Does anyone know of a solution to add these in iMIS?