I'll take a stab at this one.
Is it possible to spend a career at a Regional carrier? The answer is yes depending on which airline you choose. I can only speak for the carrier that I work for. At my carrier we have many of the same "features" of the major carriers. These include:
Company funded retirement (not the same as the big boys and girls but a pension none the less)
401k plan in addition to pension plan
Trip and duty rigs (in its infancy here)
Hard scheduling and duty limits
Full medical, dental, and vision care.
Pass benefits on Delta, ASA, Comair, and Skywest.
Pay, well here is the biggest difference. It is now possible to make six figures at a Regional, BUT it takes a long time to get to that pay level. You will have to spend many years below that wage but you will reach it if you decide to stay for the long haul.
There are many pilots here that wish to stay and not move on. The pay and benefits are suitable for them not to give up their seniority and start all over. Regional aircraft are the fastest growing segment in the airline industry. Seniority and upgrades to captain come very quickly right now. However, the quality of life and career earning potential (including retirement) are greatly limited at a Regional carrier. It all depends on what you want out of life. The choice is yours.............