Hellmuth I question the resources statement.
Commuters are for the most part flying much newer aircraft than majors. The BE1900D models are all less than 15 years old. The RJs less than 10. Compare that to the carriers out there flying B727s and B737-200s, all of which are 30 or more years old.
There is a lot of new technology in the commuters that you may lose when you go to the major. FMS, Glass Cockpit, etc.
These new stretch RJs are quite impressive. Full automation, LE devices, APUs, etc. Awesome!
I agree on the critical phase assessment, although RJ crews are flying fewer legs than B1900 and J31 crews. RJ stage lengths are starting to get pretty long - PHL-STL for example.
If there is a difference in safety it would have to be in crew experience. I know this is unpopular here, but you don't see many major carrier crews with 300 hr FOs (not even United anymore.)
The only RJ accident that I know of (I'd like to hear more about that CRJ crash that happened this year, don't know anything about it) was an ERJ that had a hard landing in RIC. Both crewmembers were decidedly low time, the CA had only 2500 hrs and her FO only had about 800.
No one was hurt but they did bang up an airplane.