"Non-contrubuting ideation" - people from other groups without real skin in the game who don't want to take responsibility for anything but insist on providing input on how it's done, and often have some political standing to do so. This has come up again and again in many roles. For me personally, I am really bad at handling this. Sometimes it's fine just to meet with people an hear their ideas (which can obviously be helpful). But other times I have had to basically say that if this other person wants to run the project, they're welcome to it. I'm aware that a lot of this is my fault and some people are much better at diplomatically handling this kind of situation. At the same time, I have led some very successful projects by taking a stand and burning political capital by keeping armchair quarterbacks away from the project.
Try assembling a document that covers how outside teams should interact with yours during project planning. Build some red tape into the process like requiring they write their own documents, go through a review process, get approval from a department head, present a demo of what they want done, etc. No good deed goes unpunished with some people. It's so unfortunate because we're all in this together.
If you're taking stands all the time, you're the cranky person who's hard to get along with and you'll be in real trouble the first time something goes wrong.
Absolutely -- although it's less manipulative than the phrase implies. It just refers to building up some level of trust, respect, and goodwill over time by being an honest, decent, and caring person. Then, when you find yourself having to make a decision that you know is the right call, but might not be well received, that trust and respect you've built up can be useful in helping your team digest the decision.