CIP/VIP is, really, just there to massage the egos of their clients, sorry to say!

Assistance is on "request" - i.e. the travel coordinator has put something in the booking.

The extent is mainly escort from the lounge to the aircraft (extends to connecting to/from other airlines at the same airport). That is usually done by someone uniformed, but sometimes ground handling. The main benefit is that special requests in the booking will be read by a staff member as part of the routine: but no guarantee on if it can be done!

It will show on the manifest, but there is no real additional treatment than that as standard. Sometimes there might be escort from check-in, but that is very rare. If the crew is not so busy, they will do things (as sydtogla has found out!).

CIP/VIP designators are most usually negotiated as part of a corporate contract to make their key personnel feel more important.

iOs will have assistance from chauffeur-drive to aircraft, through security and immigration as required, and separate vehicles will be arranged for any non-airbridge stand - that doesn't happen for CIP/VIPs unless arrangements have been made specifically (usually requires money!). The escorting staff member will always be a member of EK staff (usually the ASO on duty or senior lounge supervisor), not GHA staff in EK uniform. They also get....5 extra kg of baggage allowance.

The only people who outrank iOs are VVIPs - they will invariably have had their requirements communicated in advance, e.g. if they require EK assistance for them and their entourage, arrangement of airport passes for non-travellers to accompany them to the gate/lounge. I am told though that most VVIPs are very low maintenance: their own staff have generally arranged everything with the appropriate authorities already.