Can anyone provide 'wish-I-would-have-known' issues regarding the politics, expectations, and monetary realities of working for a major department within a large University?"
As in any job, there are good environments and not so good ones. I'm biased, of course. I retired early because of getting stressed out after moving from private sector to direct employment. Stress was a management tool: assign a task to two people, don't tell them, stomp on the one that came in second. Many universities have no concept of management, even in business schools. That is partly because the business model is unclear, success is ill defined, and no one quite knows just who is the customer. Politics are ridiculous with huge egos overlaying most other factors.
That said, pay was mid-level, retirement was good (but that is changing), there was often lots of autonomy, I got to be creative. The retirement system is paying for health care, which helps with the consequences of working there. I don't recommend giving away product, because it will be lapped up without having much effect on future jobs.
I worked for 30 years as a contractor/consultant and trouble shooter without a problem. The U-job, in 11 years, trumped all that. Be careful.