Climate in your location? If it is a humid place, I'd stay the heck away from the garage.
Garage door being open. Does that make the safe visible to the road? I would not want the local lawn guy seeing that size of a safe then BSing with every other day laborer at Home Depot about it. Also, if it is in the garage, 2 guys with the right dolly and a lift gate can roll that puppy to their truck and be gone in 4 minutes.
You mention TL30. Do you REALLY need that level of security? (I don't need to know. A question for you to reflect on...)
Is your basement finished? Will this safe be in a mancave? Can you replace your door to mancave with a
MURPHY DOOR ? I'll take a "less than tl30" safe in my home that nobody knows about, than an advertized, sitting in the living room that the fridge/AC/salesman/plumber sees when they walk through.
What prevents you from getting your desired safe to the basement; Its height or weight? When I bought my safe, the $300 for the (supposedly background checked) 4 guys to get it where it needs to go was worth it.
Have a home alarm? Make your man cave its own always-armed zone.
How far do you live from home? Buy a Liberty Safelert Monitoring System and it'll tell you if it is jostled.
Fire protection; No way around it, that is usually your biggest threat.
Oh yeah, welcome to ARFCOM. Thank you for posting in a subforum before joining the freakshow known as GD.