Sounds like BA need to review staffing levels if the queues are long - waiting for 50 bag-drops is hardly 'fast'. And I'd hope security will speed up as people get used to the new regs. In the US, most travellers know to strip and lube before approaching TSA so the lines move quickly.
As for emergency row seats... maybe mount a button on the ceiling above the check-in desk. If you can reach it, you can have an exit seat...
