You've provided an answer which you deem annoying, yet works. Contact with a motor vehicle means damage in almost all cases. There is no way to allow one large mass to slide against another without damage. (Item 2 in your post)
In an unrealistic response, you would drive your vehicle onto a caddy, lock the wheels in place and press a button. The caddy would then motor into the garage on a predetermined track, touching nothing and causing no damage. Helicopter pilots use a system similar to this for moving a powered-down helicopter into the hanger, although it's not automated.
Realistically, one could place a convex mirror on the outside of the garage near the area expected to take impact. The convex mirror is similar to those found in stores allowing the cashier to observe a wide area for traffic. In the case of the garage mounting, it permits the operator of the motor vehicle to observe the vehicle perimeters along with the building limitations and to keep the two apart.
Depending on the steering geometry and wheelbase of your vehicle and other mechanical parameters, you may have no option other than the back-and-fill method of positioning your vehicle for entry. This is a common practice used in many driving situations.
Depending on your driving skills, you may be able accomplish a garage entry in a single pass by reversing into the garage. This increases the risk of contact with the building if your reversing skills are poor and may also require multiple passes to align the vehicle with the intended destination.