Will This Be A Problem With My UK Tier 5 Youth Mobility Visa? [duplicate]

So I'm currently working on applying for my UK Tier 5 Youth Moblility Visa. I am a 21 year old from Canada.

I am worried that a past experience in the UK will be a problem, let me explain.

A few months ago I was backpacking across Europe and spent a lot of time in the UK as I lived with some friends there. I was only there under the ordinary 6 month tourist visa. I stayed for around three months and then went back to Canada. Then around three weeks later went back to pass through Gatwick Airport to Stansted Airport to catch a flight to Norway. The woman was a bit suspicious that I was back so soon but I explained I had a flight to Oslo in two days.

Then around a month and a half later, I came back to the UK for the birthday of my friend and her son. Their birthdays are close together. Frankly, when I got there UK immigration was very suspicious because I was back for a third time and soon. Also, as I backpack and hitchhike a lot, couchsurf and do all I can to save money, I have little funds and they were suspicious about that as well.

They detained me, took my fingerprints and interviewed me under recording.

After a few hours, they phoned my friend and then decided I was ok to be let into the UK. They then let me into the UK but put a special stamp in my passport. From what I understand, the stamp signifies that I need to be asked additional questions.

I stayed for around two months as we all made plans to go to Portugal together which I didn't expect. Then we did and later I went to Ireland by myself.

During my time in the UK, my friend paid for my food and let me stay at her place. I got funds from my parents but not through my own bank account. (should I mention this on my application?)

So I was not refused entry, so I've already decided that I don't need to say that I've ever been refused entry into the UK on my application.

But they will be taking my fingerprints when I send the application to the visa center in my city. So I will probably show up on their records. I don't want them to look at me in any bad way whatsoever. I loved the UK and I very much want to live there for two years. Will this hurt my chances?

Should I mention this incident on my application so it doesn't seem like I'm trying to hide it?

I'm thinking if I don't mention it, when they're processing my application and do research they might see me show up on the system and automatically deny me because they're assuming I'm not trustworthy.

Also, will my history in the UK as a tourist and not spending money be suspicious? How can I counteract this? I will have enough money in my bank account to apply but during my time in the UK this bank account was mostly empty as I got help from my parents. I spent very very little money anyways. Around 100 pounds per month.

I could really use support on this. Thank you.