My issue wouldn't be proving to them that I won't be a charge on their system- I have my own health insurance, money, and I'd have a return ticket/hotel booked. I feel that after hearing about how strict security in the UK is, however, my arrival from the country I am currently in instead of from the US would send up flags on its own, regardless of any dates on my passport.

As for the European security, no, I was not talking about border patrols within the Schengen area. I printed out my own boarding pass and checked my luggage when I arrived at the airport. When I entered security, they barely glanced at the boarding pass, and didn't ask for any kind of ID. When I boarded the plane, once again my passport was not checked closely against my boarding pass. I was not referring to border controls, just to a glaring lack in basic security.

Odin - I never said travel insurance - I said health insurance. Most americans would have health insurance either through their job, or through their university of as a child of working parents (up through age 26).

And I have been in and out of England at least 20 times - and know that as an adult who looks like a business traveler I don;t get asked these questions. The only things they ask are reason for visit (vacation) and hotel (supply name) and thank you madam.

As for the OP - considering their history I would assume they would receive special attention and very possibly not be allowed to enter - but simply sent back to where they came from.