Given a travel related situation, and given a specific question about the situation, summarize the question into a title

[EX Q]: So the following conversation took place at Gatwick Airport in April 2015, around 10:30PM, as I was entering the UK on a Swedish ID card. I was dressed in jeans and a plain red t-shirt (it was warm outside), had a laptop bag for hand luggage and was sober.

(I look southern European, perhaps Bulgarian, and speak Estuary English - basically like Gordon Ramsay accent-wise)

IO: Where are you arriving from?

Me: Zurich

IO: Where are you headed to?

Me: London

IO: What will you be doing in London?

Me: Just visiting

IO: For how long?

Me: A week

IO: Where will you be staying?

Me: At a hostel in Dollis Hill

IO then looks at my ID and scans it with a UV lamp. After 30 seconds

IO: Do you have another document?

Me: Er, such as?

IO: Dunno, bank card, library card, driving licence, anything.

Me: Nothing with a photograph I'm afraid, but here's my debit card (handing in my Maestro card)

10 seconds later...

IO: How come you've got a Swiss bank card!?

Me: Because I live and study in Switzerland, in Zurich

IO: Since when?

Me: Autumn 2014

IO: What do you study there?

Me: Computer science, at the federal institute of Technology

IO: Towards what degree?

Me: Bachelor

IO scans the ID, and 30 seconds later...

IO: Alright, have a good evening.

The question in bold is among the weirdest questions I've received from immigration anywhere, although thinking about it, I suspect the officer had her doubts about me actually being an EEA national.

Is this the likely reason for the unusually long landing interview (for an EEA national)?

On some previous occasions I've cleared immigration at the same airport, under identical circumstances, without a single question.

[EX A]: Strange landing interview at LGW for an EEA national

[EX Q]: I know this question was asked many times, and I read most of the answers, only my quest centers on the time that has passed since my overstay.

Briefly, my story is I visited the US as a tourist from Argentina in 1993, and being there I wanted to try the experience to live there for a while, rented an appartment, could get a basic job as a driver doing deliveries, and ended up living for about one and a half years. After that, and realizing living as an illegal was a deadend with no promisory future, I just picked my things, bought a plane ticket and departed in 1994 never to return.

Long story short, after almost 25 years, now I'm a professional, have a good situation and would just like to make a short vacation there.

Here's my main doubt; I'm not sure if it's convenient or relevant to mention my overstay when applying for a visa, considering after such a long time they may not have record of that; or do Customs keep records for that long, and could backfire me here at the Consulate, or upon arrival at the airport?

I add additional information
To make things more interesting, I also have an italian passport. Since I am of italian descent I own the double citizenship. This passport grants me VWP, but that doesn't guarantee automatic entrance, that's why I chose to go with the argentinian one which needs a visa. I assume that having a visa makes entrance more likely since you underwent a previous official scrutiny; or does it not? Besides using a different passport could seem an obvious way to dodge that scrutiny and make it even harder.

[EX A]: Getting a B2 visa after an overstay almost 25 years ago

[EX Q]: A few weeks ago, I booked a flight with Transavia going back from Prague to Paris on the Wednesday 10th June 2015.
Yesterday, I received an email saying "your reservation has been updated, click on the following link to see the new time for your flight" and on the linked web page, the flight appears to be on the 12th June.
I have not acknowledged the change yet.

Changing the "time" of the flight by 48 hours seems a bit extreme to me.

Is that legal at all? Is there any procedure to ask for compensations for the additional time off work I'll need to take or for the extra hotel nights ?

[EX A]:
Flight rescheduled, what are my options?