6) The documentation should mention that when the 'timezone' parameter is not set explicitly, the current timezone is used.
fixed
7) Why do the functions accept only the timezone abbreviation, not the full name? I find it rather confusing, because the 'timezone' option uses the full name, and we're using this as the default. But doing 'show timestamp' and using the returned value fails. Is it possible to fix this somehow?
A only abbreviation is allowed for timetz type. Timestamp can work with full time zone names. A rules (behave) should be same as input functions for types: timestamptz and timetz.
postgres=# select '10:10:10 Europe/Prague'::timetz; ERROR: invalid input syntax for type time with time zone: "10:10:10 Europe/Prague" LINE 1: select '10:10:10 Europe/Prague'::timetz; ^
I enhanced a regress tests. I found so work with time zones is not strongly consistent in different use cases. Operator AT TIME ZONE is more tolerant, but I use a routines used in input functions and my target was consistent behave (and results) with input functions.