When you publish model to cloud from Revit you don't know at the time what the links will be to individual sheets on ACC/B360 (not sure if they are stable across sessions or not). So there is a task with B360 API in first associating the sheet name or other identifier to the linked location it ends up being (if that is even possible, seems it should be) and part of that includes dealing with OAuth etc. You would have to investigate how such information is retrieved via web requests after being up-loaded to B360 (there is nothing in Revit API that will help with that task). You probably find that a user being signed on in Revit doesn't give them access to B360 outside of Revit (without having to sign into that separately).
Also publishing to ACC takes an amount of time and when you publish model to cloud there isn't always the requirement to publish the sheets with the model, often pdfs are published separately to model. So are you talking about viewing the model in ACC/B360 and seeing the sheets that were published with it or linking more generally to pdfs in files area (separately published).
The second part of you task it seems is to retrieve a mapping of elements to views. There isn't a one to one relationship between elements and views in the first place since elements may appear on multiple views. So there is a task in deciding which view is the best candidate to link to via other information such as published sheets lists and how relevant the sheet is to the element in question. So as an example a steel beam would be seen on a metal deck layout drawing, a steel plan GA and various sections (you would have to decide that you care most about the steel plan GA or give the user all options to decide).
So the second part of you task can be advised upon here but the first part probably not.
