That Stander's Anthem is from the Rejoice Ministries website. They are too literal for my tastes. I like them, but not the religious strictness. I don't think salvation requires a Christian Faith--though I am Christian (proudly Lutheran!).
You can Stand now and stop Standing at your discretion. From your description, I would classify you as a person who is Standing, but you are not a Stander. In the strictest sense, it is a Covenenat Keeper, and remarriage is not acceptable. Once married, always married until death.
I realize you are defining moving on withio the context of waiting around for your spouse to return, never dating etc. In that sense, yes it means never moving on. I define moving on as getting a life and being happy with my Self...while Standing. That is one of the greatest challenges for many out there. They keep Hope so close rather than putting it away in a precious box and letting it live without relying on it. Hope is not something to which you have to cling. It will still be there when you Let Go.
You have a healthy view. You ar doing well. You don't have to do this forever, and it seems you have accepted that your MLCer may not return. It is different for everyone. Would I have so strict had I not known Sweetheart would return? I cannot say since that was not the condition of my situation. I always KNEW he would return.
So I try not to hold others to my strict level. You need to determine what is best for you and where your beliefs are.