PE Case Study with IC Memo

Hi guys, I'm taking a 3-4 hour long case study as part of an interviewing process. Just want to get some advice on it. I know the case study will involve reading a short CIM, putting together a full model (I was told there will be a template), then putting together some pages/slides.

For the model assumptions, I assume that as long as I can defend my assumptions I should be good. But does anyone have advice on how to make sound and reasonable assumptions (i.e. use historical CAGR and adjust for recent trends/activities)? And for the memo, I know that it should include exec summary with recommendation, company overview, industry overview, key investment highlights, risk and areas of diligence, and perhaps a model walk thru. Anything else I'm missing?

Thanks for the help guys.