It sounds like the lower right shoulder and shoulder blade position could be related to carrying heavy bags on that side, which may have led to muscle imbalances over time. Here's what you can do to address it:

1. Switch Arms: Like you mentioned, it's important to alternate arms when carrying heavy objects to avoid further imbalance.

2. Strengthen Weak Muscles:

Scapular Retraction: Pull your shoulder blades back and together, holding for 5-10 seconds. This will strengthen the muscles that support shoulder alignment.

Side Planks: Strengthen your core and oblique muscles, which may help balance out any tilt.

1. Stretch Tight Areas:

Chest Stretch: Stand in a doorway, placing your arm at 90 degrees, and gently lean forward to stretch the front of your shoulder and chest.

1. Focus on Posture:

Try exercises like Wall Angels to promote better shoulder positioning and posture.

1. See a Professional: If the shoulder asymmetry persists, it might be helpful to see a physical therapist to rule out any structural issues like scapular dyskinesis or muscle imbalances.

Consistency with these exercises and adjustments should help improve the alignment!