Concerning your last question, a few similar words:

• altmodisch – old-fashioned
• ungebräuchlich – something is rarely used (no statement concerning the trend).
• außer Gebrauch – out of use.
• außer Gebrauch geratend – something is becoming out of use.
• archaisch and antiquiert – emphasising that something is old (older than something that is veraltet). Some people may still use it anyway.

The following three classify whether it still makes sense to use something but not how often something is actually used (something überflüssig may still be used by the majority):

• obsolet – something is not really required or needed anymore
• überholt – something that has been replaced (lit. overtaken) by a new standard.
• überflüssig – something that grants no benefit anymore (superfluous).