Re: bogging down
If you heat the area around the broken bolt...the aluminum only...and then use the center punch at a right angle to the direction of rotation, tap gently and the broken off piece will slowly come out. Once a few threads are exposed you can grab it with pliers and remove it the rest of the way.
Try to direct your center punch on the easy-out! Do Not heat the aluminum too much, and make sure you direct it away from the easy out/steel stud that remains in the engine. You want the aluminum to expand, not the steel.
You can try this without heat! If you are patient it will work without heat!