Ronin, when I converted to Autopianism and detailed an engine that had been neglected for 2 years, EFHI/citrus was a gift from Heaven! :up I'll continue to use it on the hardcore cases. And brake-parts cleaner was great on the lower-engine parts. (Just don't make my mistake and use it near the spark plugs while the engine is running!

) But when detailing engines that have just had a few months of neglect, I find I can either dilute EFHI or use less-expensive products like Orange Blast or diluted Simple Green. In those cases, I don't try to spray-down the whole engine; I just work on one component at a time, spraying with the product, and cleaning-up (maybe using a couple of applications) with a shop towel. Then I hit the rubber hoses etc. with something like gummipflege, the plastic with Plexus or another plastic "polish." Still trying to decide about the "bright metal" parts (like brake master on my '75 car); I know carnauba's useless at those high temperatures, but haven't yet tried a polymer sealant and QD as some here have suggested.
To answer your more specific questions, based on my experience:
- Yes, it's great at grease-cutting.
- No, it does not damage hoses, rubber, etc.
Keep firing-away with more detailed questions if we're not really addressing your concerns. And keep us posted on your progress.