Great news on your first post op, Mersada! Don’t stress about lifelong precautions. I’m betting it will become second nature and if you ever accidentally break the safe guard, I’m sure you’ll be okay. It is an easy enough habit to develop and live with given all you’re gaining through the gift of this surgery. Just as you’ll adjust and become more comfortable with your new hip and the thought of it will leave the forefront of your mind, surely the habits you develop will also become natural for you.
A couple phrases I heard to help remember which leg to use when navigating stairs were as follows - "Up with the good, down with the bad" and my PT’s favorite was ”good goes to heaven (up) bad goes to hell (down). The second was my least favorite, but it was easy to remember and helped me form the habit.
I didn't even think about leg shaving. How the neck are you supposed to do it??
This is an option -
Giraffe Razor Extension Handle
Telescoping handle adds 15-20 inches in Length to a Razor Handle - Eliminates Bending at the Waist
Pivoting Head Rotates to a 30°, 45° or 90° angle - Maximizes Flexibility
Two Universal Razor Attachments, Small, and Large - Accommodates the Most Popular Men's and Women's Premium Disposable and Reusable Razors on the Market Today
No Slip Grip with Rubberized Finish - Perfect for Anyone who has Difficulty Grasping Objects
Quick Connect and Release Buttons - Ease of Use

I’ve also read of less slick homemade versions using either a wooden paint stir stick, or a 12 inch ruler taped securely to a disposable razor.
I hope you have a nice holiday weekend!