Most maintanace functions can be done in SQLExpress through SQL Server Management Studio, but manually. Most Express instances are maintained when a DBA gets around to it, with utilities developed by vendors of the applications hosted on them, or only when something breaks.

In my opinion, SQLExpress is appropriate for 1) Configuration databases that are rarely updated (when they are they should be manually backed up and copied off server), and 2) testing complex scripts or commands that you're nervious about running on a DEV server the first time.

That said, it is possible to script out maintanance routines and run them from the command line via Windows Task manager, but the more databases you have, the more unweildy and time consuming the management of this will get. If the data is that important and you don't have 3rd party vendors with their own maintananace tools, consider at least getting Standard Edition.