Excel Help

my current role has me working and updating an excel book of 20+ deals thats roughly 80-100 tabs and 80-100MB. I then need to pdf it and send it out. The book contains commentary and financials which are updated quarterly.

First question, instead of working on the deals in separate smaller books and putting them together at the end, how do you speed this book up and or reduce the size? It slows my computer down so much I have to restart. I’ve compressed the pictures, reduced formula use, but not sure where to go from there. 

Second question is formatting. When the book was created it was done by about ten people individually working on deals so there is a ton of discrepancies with formatting and titles/headers, etc. While all tabs follow the same three or so patterns they aren’t exactly the same. What’s the best way to go about making it uniform and clean when it’s PDF’d?

Any other tips or advice from people who have been in similar situations?

ive been thinking about just creating a new book from scratch and doing it myself but that’ll be time consuming. Once the book is finalized, I’ll really just be updating financials quarterly or semi-annually. 
 

Any advice? Thanks.