If you could arrive early tomorrow, we would be able to finish the project quickly.
we WILL be able to
If he hadn't been taking so many risks, he would have fallen off his bike.
...he WOULDN'T have fallen off his bike.
If you've decided not to go to the film with us, we would completely understand.
we WILL completely understand
If you booked the flights, we could look for accommodation.
correct
There will be no point in asking her any more questions if she's still refusing to talk about it.
THERE'S NO POINT IN ASKING....
If he's decided against taking the new job, he won't have relocated to a different city.
he WON'T BE RELOCATING to a different city.
If it hadn't been for the terrible weather, we might really enjoyed our holidays.
...we might HAVE really enjoyed.
If you don't overheat the coffee, you don't ruin the flavor.
correct
If you would book the flights, I'd really appreciate it.
correct
If you help me with the supermarket shop, we can finish in no time!
correct