Reverse-engineering is legal in US and EU for interoperability purposes only, if I understand correctly. I don't think reverse-engineering drivers can fall into this category, even though reverse-engineering drivers are many.
Sure, you can stay in some country where the local copyright law is less tight and less enforced.
And, Yes, redistribution can be a problem in theory (still depends country, I believe). But I cannot see how CyanogenMod could potentially irritate phone vendors. Don't over-estimate Android version's impact on phone lifespan.