2) Human beings announcements
Most of all at Cardiff Central, where you get that irritating shouty "not for passenger use" man deciding to negate
TfW▸ 's entire Welsh language policy by interrupting the Welsh-first announcements and shouting exactly the same thing several times in English only in a thick Cardiff accent. That guy definitely belongs in Room 101, or failing that a ticket hut in Coryton or one of those branch line stations.
Whilst we're putting Cardiff Central's staff in Room 101 or ticket huts on branch line stations, those pointless customer-be-damned orange bibs on the Valley Lines platforms are ripe candidates for redeployment.