You CAN lock the bronco with the key inside when you use the number pad. I do it daily. It's no different than any other key fob. It's only when you use the door lock button from inside that it complains if the key is inside.
I put the 6112s on my 2 door base SAS. I didn't add anything else. I'm still running my stock 35s, so for you if you use the 6112s even on the highest setting you shouldn't need anything else. I was able to get the alignment good also. It does ride a little stiffer, wish isn't bad except for one...
I have this exact model. A '23. My opinion is it's the best config. Least amount of electronic gadgets to fail, best available running gear, and so much fun. Get the SAS, you won't regret it.
I'm surprised I don't see more comments about the Thor setup. That's what is on my list. I've got a ViAir compressor on my truck and I've used them before. They are ok, they last a lot longer than but are much more expensive than their Chinese knockoffs.