Can these bee stings feelings in feet come from sitting in same positions for long hours? and from flip flops?

Absolutely: That pins and needle sensation "after your leg falls asleep" is due to blood flow returning to a previously crisscrossed leg, etc... When crossed with pressure, your blood flow and nerves were being squeezed (not dangerous) - and you feel as if your leg is asleep. When blood flow returns, the nerves initially fire randomly resulting in the pins and needles sensation.