Re: rear suspension end bushes
They're about £18 each, just for shaped bit of yellow rubber! You'll need to remove rear spring by lowering rear suspension arm (unbolt shock first), pop the pokey out bit of the new bump stop in place in the hole in the car (you'll never get it completely in its hole just by hand), then jack the suspension arm up without the spring in place to try and push the bump stop in place - kind of twisting the bump stop whilst applying pressure with the jack seemed best.
There's a fair chance you'll break the plastic pad at bottom of the suspension spring when removing the spring, which was nearly as awkward to get back in place as the top bump stop, but you can replace that without removing anything, just need an appropriate lever!
It's not at all dangerous to drive without getting it fixed urgently unless you do regularly get air over speed bumps etc.