An easy out will be hard as fuck so your have trouble getting that out! If your taking the engine out you could have the easy out and bolt spark eroded.
As for the hole in the water jacket if it's a cast block your have to cut a thread into it heli coil it and seal a grub screw into it! But best done with a tapered thread and if you do use a tapered thread you won't need a heli coil If the block is alloy see if some one can plug the hole