I think at the end of the day, my back and my knees are of more value than saving a few dollars on gifts, but to each her own. I do think it creates a somewhat dangerous situation for a woman traveling alone to be encumbered by heavy bags. It does make her more vulnerable than someone who can move quickly and alertly. So, no, I wouldn't have two 50 pound bags plus carry-on when traveling alone. It seems a foolish economy to me.
I realize there's a gift giving culture in Asia, but I'm from an American culture (the South) where it is pretty easy to drop people from gift exchanges without giving offense. I have an extremely tiny gift exchange list, and I mostly don't get involved in buying gifts in the first place. If someone wants a souvenir from my trip, they get a photograph. But I realize this doesn't work for all cultures.
Let me suggest this for your left arm. I had rather weak upper arm strength myself, and I needed to develop it for my hobby of birding, so I could hold the binoculars steady for many hours. If you practice lift light weights, but multiple reps, you would be surprised at how quickly that muscle in your upper arm gets strong. I'm talking, within maybe three weeks, you will feel a noticeable difference and be able to handle more weight or longer periods of lifting. Give it a try!