You HAVE to take the flights to get the tier points. Even though Bronze status isn't great, it's still more useful than people would say, especially getting to pick seats 7 days before flight time - basically guarantees no possibility of a middle seat (It's rare but not impossible especially if you don't pay for seats and you forget to check-in 24 hours early), also having a selected seat makes it way less likely you'll be downgraded or booted onto another flight if they overbook the flight.

You can earn 20 tier points pretty easily: either 4 short-haul flights on the very cheapest economy tickets (e.g london-manchester or london city-amsterdam in Economy Basic I think) or 2 not quite so cheap economy tickets (Economy Plus think) or 1 ticket in the refundable Economy option (Economy Flex).

Given you still have 3 months left, you might want to even consider going for BA Silver status which is WAY better than Bronze. Silver status gives lounge access across all Oneworld airlines and at booking seat selection. I think you could do it with either a return flight from Dublin via Heathrow to the East Coast of the US in business class or via one or more BA holidays with the double tier point offer.