Questions about tourist/visitor 6 month visa

Hello,

Here is my situation. I am a US Citizen. My girlfriend is Irish and is working here on a short term contract until December.

Once her contract is over, we are relocating to the states. I have enough money saved up to last me the rest of her contract.

I arrived with her from Dublin on March 21st. I came through Heathrow without any immigration officials checking my passport, as there was no one there in the Terminal. I am leaving to go back to the States to visit family on June 3rd. I would like to come back to the UK on July 1st on a tourist visa and stay until December and then go back home permanently.

My questions:
Will I be eligible for the full six month visitor visa on arrival into Heathrow on July 1st?
Should I tell the immigration officer that I am planning on being in the UK for the full 6 months? In other words, should I just directly ask for a 6 month stamp?
My current trip, since it has not been entered into the biometrics system, should not count toward my 6 months, unless they ask me directly about it, correct?
Should I fly back through Dublin on my way back to the states to avoid UK immigration stamping me on the way out? Do they even check people leaving, or just arriving passengers? Basically, I am trying to avoid this current stay being "on the books" so to speak.

Are there any other issues I should be aware of in this situation?

Thanks so much for your time.

If the IO suspects ur are effectively living here on a vv or are spending more than six months in twelve here you are certain to be bounced.

Too risky for me.

Wanderer wrote:If the IO suspects ur are effectively living here on a vv or are spending more than six months in twelve here you are certain to be bounced.

Too risky for me.

Okay, two hypothetical situations for you.

I fly out and back through Dublin, where apparently there is no immigration control. Then just take my chances getting picked up on the street.

or

I tell the IO I am staying for 3 months and then apply for an extension, staying while the app is being processed.

If you say you are staying 3 months, you will almost definitely get a 6 month stamp.

Visitors generally get a 6 month stamp by default.