it's something I've considered. To be honest I should really just sort out a proper visa and register myself at her home when I arrive. Its just further down the pecking order than sorting my sons uk passport and my girlfriends visa so they can come to the UK.
Since August I've entered 3 times using visa exemption i never extend due to work rotation. I've never had a problem but I was asked by the last immigration officer where I would be staying. I told him with my girlfriend first and then her family for New Year. He accepted this without any further questions, I even offered her address and phone number when he asked but he wasn't interested. I got the feeling he asked because he had to, not because he wanted to or even cared.
I fly with Turkish Airlines but I think its more of a Libya thing than a Turkish Airlines thing. They are trying to show that the airport in Tripoli is responsible and that it has a high level of safety so they can get more direct flights in and out. I've never been asked when flying from the UK.
I was just joining in with the OP. I actually get asked this question everytime I fly from Libya to Thailand. I also have to show the people at the airport proof of a visa or the website that shows I can enter on under the visa exemption.
this isn't necessarily true. If all you're doing is withdrawing small amounts, say 10k each time, you are better off exchanging cash of you find a decent exchange rate and are exchanging £50 notes. However as the OP is asking about maximum withdrawal, you can get a better deal withdrawing 30k baht from my revolut card than I do exchanging cash.
My girlfriend has been to the UK 3 times now, once on a 6 months visa and then the next 2 times on the same 2 year visa. We never had any trouble with applying for he visa, we did all the application ourselves without the use of an agent. The UK government website has a list of things it needs and we gave them exactly what they asked for.