There are many questions here that need to be answered, but most of it starts with, "It depends." If a person has more than the 5 or 6% that is matched and wishes to put that money elsewhere, there are many options in putting together a set of retirement investments. Some employers are willing to work wth an employee by sending money off to desingnated retirment accounts not associated with a 401k, other companies want nothing to do with this task.
A Roth IRA is wonderful because although the money is not initially tax-deferred, it will not be when taxed later when presumably a larger nest egg would be taxed at a higher rate. You do not need to pay taxes each year on a Roth IRA. The tricky part is that the rules differ on how much a person can contribute, and it just depends on how much you make a year. There is a myriad of investments that are relatively safe and diverse enough to make a retirement portfolio run fairly smoothly. However, most people should work with a competent, licensed financial advisor to develop a roadmap to a secure financial future. Even people who understand complicated investing and feel competent enough to manage their own finances can benefit from having fresh eyes on their financial planning.