Nope, an employee can certainly opt to pick their own investments! Though we've found that the vast majority of employees don't want to bother with choosing funds and doing the work of managing and rebalancing their 401k accounts themselves.

Yes, we have access to Vanguard's lower-fee admiral funds. Companies can pick which funds they want in their 401k plan, although most choose a standard lineup of Vanguard index funds that spans across all the major asset classes and risk categories.