londonblue...
Your first query - yes, of course - and most of the time, I would hope.
CAP774 tells you...
ATS provision
1.5 Controllers shall make all reasonable endeavours to provide the ATS that a pilot requests. However, due to finite ATS provider resources or controller workload, tactical priorities may influence ATS availability or its continued provision. Therefore, a reduction in traffic information and/or deconfliction advice may have to be applied, and in some circumstances an alternative ATS may have to be provided in order to balance overall ATS requirements. FISOs are not licensed to provide Traffic Service, Deconfliction Service, or Procedural Service. Therefore, pilots are not to request any of these ATS from a FISO unit.
FISO units are established to provide ATS at notified aerodromes and Area Control Centres (ACC), and can be identified by the RTF suffix ‘Information’, e.g. ‘London Information’.
Your second point...you are correct. In fact, the AGCS does not count as an air traffic service, by definition. Although one could be forgiven for thinking that it was an AFIS - on the cheap, unlicensed and unregulated - in some cases!
2 s