How many of these are actually true as a rule? I would have said zero. Again, it makes a big difference whether you're talking about a E-170 or a CRJ-200. Maybe the E-170 and up aren't even "regional jets"?
E-170s are operated as mainline or at mainline service levels by other carriers, including the cheapskate Air Canada, where they have F, IFE, and even serve hot meals in F and have BoB food just like mainline AC (and not just on 3.5+ hour segments).
"Regional" partners do what they're contracted to do.