If you're not concerned about meeting any codes, swing the door any way you want, your local codes in fact, may not even address the issue. The security of a residential grade door and jamb assembly is total ****, so don't let the supposed security advantages of one over the other sway you.
While everyone wet's their pants over the hinges on an outswing door, it's almost universally addressed by the manufacturers by supplying the outswing units with security hinges. The weak spot is the latch/ striker area. You can typically pop one of these doors with a small crowbar in about the time it takes to open one with the key. But by looking at your pictures, the best way to outswing the door would be to install a left handed unit which will hit your radon mitigation ventilator unless you provide an additional stop but at least you're not setting the door up to totally leave the building in a strong wind. It's doubtful that snow would ever be an issue where you are located, so that's not a concern.
Someone posted about leaving the concrete "as long as you didn't mind a couple steps". There's not a code in the country that allows this. Swinging a door over a step is not permitted. Most municipalities require a landing, not more than one step down from the threshold that's as wide as the door and at least 3 feet in the direction of travel. So if you have an inswing, you need a big honkin landing inside the garage and a step to reach the landing if the elevation requires it. If you have an outswing, you need the landing on the outside of the building and steps as required for the interior.
Your best bet is to cut the stemwall wide enough for the door unit and the associated framing. This will eliminate any step inside the building and quite possibly put the threshold just one step up from the exterior.
Attempting to cut the siding and sheathing at once is a total waste of time because you still need to remove the remaining siding to attach the J channel around the door unit.
The correct approach would be to strip the siding, mark and cut the concrete down flush with the slab, (unless you have done this before, hire it out, cheap, fast and accurate) frame the opening and cut out the remaining sheathing.Then install your door and re-apply the siding.