Garage Door Openers: Sounds like chain or belt will work, I've had both, no problems. If you can't find a good garage door opener sub, I installed two garage doors openers at my old house in a weekend, so it's a doable home owner project that is quite deferrable to a less stressful time. I suspect if you ask about an install of the doors them selves with and without an opener, you might get a better price on the opener.
Door locks/hardware: We got all the door handle hardware in for our house. About a month later the entire style was discontinued, we scrounged and got 2 spares. So order what you need and get 3-4 spares. We've had one handle that is on a pull out style door break, we're now at a no spare point. This was a handle on a door you pull with a latch at the top (double doors into a pantry closet), but these are the levers that are part of Universal Design and visitors think all door handles are push down to open, like a single door in a casing.
We keyed everything to one key. Ordered all the hardware at once at a box store, it was a small charge to have the keying done. We also put a keyed door handle on the 1st floor to basement door. That way, if we every wanted to change a single lock on the outside basement door, we could allow access to the basement but not the entire house. The garage door to inside the house is also keyed for the same reason.
We have deadbolts on all exterior doors. The garage to kitchen is not deadbolted. Some doors have half light glass in them, they are a keyed dead bolt. Others are 1/4 light at the top, they have a hand turn (no key) in them. In particular, a door by the master bedroom to the outside (which is basically a fire escape door and not used for anything else) has the no key dead bolt on it. If a half or full light glass door with a keyed deadbolt is a door you would use to get out in an emergency, have a nearby place to hang a key. At our old house, we had a small curtain over the half light and left the key in the deadbolt at night. Odds are greater that we'd need to get out in a fire than we'd have a random home invasion. If this is not the case where you are, you've built your house in the wrong place :laughing:.
Security system wise, you'll want a sensor on each outside door. I looked into using hall effect sensors to figure out if the deadbolt was thrown, it was doable but a nightmare given access issues to the trim around the door. Also looked at plunger switches, it was a lot of fabrication that I had no time for when I was in the fog of construction. So what you get with the security system is it will complain if you got to night or away mode and a door is open. It will yell if a door opens and it's night mode (you're sleeping). You'll need to check doors and deadbolts manually to be sure they are locked. I have my system programed to ask "Why is the <xxx> door still open" if I leave a door open for more than 10 minutes. Big win.
I wish there was an easy way to integrate affordable door locks into all the outside doors of a house, and maybee something has come along in the last 3 years. For now, I have the nightly door and house check to make sure everything is locked, all lights off, all cat doors shut and all critters (2 or 4 legged) accounted for. The locks are just part of that routine. There are days when the house of the future seems like it will always be in the future.
Enjoying your progress, keep going.
Pete