Freedom Pass, TfL Staff Pass, etc: Require touch in and out?

[MikeWh]

Or another reason is: bringing a full-sized bike which would require avoiding deep tubes.

If you want Liverpool Street with a bike then it's a very short ride from Shoreditch High Street. For Euston you could walk from Camden Road faster than the two trains via Willesden Junction would take, even allowing for the fact that you're on the first one anyway.