Work Intensity at Various Deal Stages

Sorry for the crap answer, but it totally depends on the team and deal. Diligence can be absolutely whack if there is some unrealistic timeline trying to be met. CIM/CIP drafting can be cake if the VP knows the MD’s style and there is a previous reference that makes things easy for the analyst. 

I’d classify stages a bit different than you did. But here’s my general view:

• pitching—I viewed this as the worst. There’s never a limit to the number of turns and there seems to be endless iteration until the literal very last second. There also is lots of vague comments like “make better” or useless bullshit like, “I don’t like the color scheme or shapes”. It also seemed to be consistent late nights with people being very on edge. 
• Drafting—I viewed this as my favorite part of the process tbh. Building the model often allowed me to dictate timelines and I could basically have no work other than “x is working on the model”. Drafting the cip/cim is kinda shitty when starting out, but once you have a bunch of previous references and get how to use PowerPoint quickly it becomes not that bad. Also, once you get fast enough at comment turns and the bs or once you are no longer the one doing the shit parts (likely when you are a 2nd year), the cip/cim drafting becomes more about actually thinking how to sell the business, which is more fun and requires thinking. Still, I have had this process be an absolute nightmare when we were trying to get out to market quicker than realistic or when the company management is particularly opinionated or disorganized.
• Marketing—reaching out to buyers is incredibly variable. Some processes can be a one-off with a single buyer, others can involve literally hundreds of firms. Marketing and keeping track of reach out to hundreds of buyers can be an absolute shit-show clusterfuck. Reaching out to 10 is really easy.
• Management presentations—usually pretty easy, the MP should be coming from a lot of the CIM/CIP if you are working with someone who isn’t a dipshit. It also should be being done in the background as you market, so it shouldn’t be bad. This can suck if you have constant calls or MP’s while also trying to complete work in the background. Makes it where you have less hours in the day.
• Diligence—completely depends. If the company is organized and the buyer not an ass, it isn’t that bad. If the buyer sucks, this can be pretty brutal. Generally, if there is competitive tension diligence goes fast and isn’t a pain, if the asset is crap, it can be really a brutal exercise. 

Writing this out makes me realize how much speed of process and the buyer dynamic dictates the degree of shittiness. Teams also are the curve ball, where if you were my junior analyst we were going to ball out back in the day, but if you got mean associate Matt, every part of every process would have you seriously considering quitting or if this was the right career path.