Swiss International Airlines - Swiss First Lounge access rules

I have looked in the forum and can't find exact answer to these questions, so hopefully some of you will know.

I'm travelling to Zurich in First and a friend I have just discovered will be on the same flight in economy. Neither of us hold status with Miles and More now.
I understand that I am allowed a lounge guest being in First. My questions are:

1) Does this include the 3rd party lounge in Delhi?
2) I understand we have to arrive on the same flight, but am unsure if this also has to include the same onward flight. On arrival in Zurich my friend is going to be flying on with a different flight from myself and maybe not even a Star alliance flight. Can I still bring her in as my guest?
3) I haven't booked my own onward flight yet. It will likely be either Swiss or BA. If I am going from Swiss first to BA, will Swiss still allow me access to the First lounge?

I just had a thought, would my friend be able to join me for a drink in first class after the meal service, as BA and some other airlines allow?

I just had a thought, would my friend be able to join me for a drink in first class after the meal service, as BA and some other airlines allow?
my answer: probably not,
but if the cabin is empty you could approach the pursuer nicely and ask.....it doesn't hurt .....

I don't know where you picked up the idea that when flying in (LX/LH?) First, while holding no status, you are allowed to take a guest into the lounge? That's not the case.
Same for having your friend join you for a drink in First..... but you can always visit her in Y...

And access to the Zurich First lounge is for departures only I think. You will however be able to use the arrival lounge.

I don't know where you picked up the idea that when flying in (LX/LH?) First, while holding no status, you are allowed to take a guest into the lounge? That's not the case.
Same for having your friend join you for a drink in First..... but you can always visit her in Y...

And access to the Zurich First lounge is for departures only I think. You will however be able to use the arrival lounge.

Flying F on LH/LX w/o *G status you are allowed to bring a companion that is flying on the same flight as you are or a connecting flight (same day arrival F BP in fra/muc/zrh)...you can access LX/LH F lounges after arriving w/o having a connecting flight (FRA FCT is an exception)

I guess I was wrong about access for an additional guest. But access to the First class lounge at arrival seems unlikely if I look at this access policy?:

Our lounge access policy for First Class passengers is one (1) companion only, plus your immediate family (spouse/partner and children under the age of 18) departing on the same flight as you.

I would have assumed that a guest would be allowed on arrival also. If they allow it on departure it would create customer service perception problems if 2 individuals travelling together on the same flights were only allowed lounge access before one of the flights.

It's the details about whether the nature of the onward flights influences things I would have thought would have been the question.