I think the advice is great.
But, I would add that I think it's good to set boundaries if you need 'em. Our culture puts a lot of pressure on Bridesmaids to be totally self-sacrificing and it can be blown out of proportion, with the ideas that people need to have several parties in addition to the wedding (engagement, bridal shower, bachelorette, whatever else). IMO. (And I am currently planning my wedding.)
If you really want to do this for your friend, that's great. It sounds like she is a good friend; if she is, if you feel you need to avoid certain situations, she will understand, bridesmaid or not. If you need to leave a party early, maybe you can offer to help her do grunt work (like assembling favors, or something) because you want her to know you want to help and be there for her?
Just some thoughts!