Hi, love all the answers for this question. I guess the OP's last question "is this just how these relationships work?" is what made me decide to join and answer. So this is my very first post.
I was in a TPE relationship for 14 years. And it's been my experience that any type of relationship is fluid. You can set up the dynamics to fit whatever situation you are in. However there are some basic foundations that can help make the D/s TPE relationship a positive one.
Basically, TPE means that the sub gives up negotiating power. I had no hard limits, no safe words, no use of the word 'No'. However, my Dom's responsibilities rose two fold. He had maintain my total trust, because he held all the power. That's not easy. It takes consistency, and a selflessness on the part of the Dom to achieve that level of trust. He was responsible for my emotional well being and his decisions had to reflect that. He had to put my needs at the forefront while still having his needs met. In return, I put his needs first and surrendered any and all self protection I may have wanted to retain, and let my Dom take over that role. I worked full time, I had children, I was still independent enough to make my own decisions regarding my health, family relationships, and my job. I was no doormat. The trick to the entire D/s 24/7 LTR dynamic is to be with someone who matches you. A Master/Dom has to be completely open about what his needs are and what he will expect and has to remain true to that. And if his needs and expectations are within the scope of what the sub/slave believes, then you"ve got a fantastic foundation for carving out whatever TPE dynamic you wish. For example, a Dom can't hide a secret desire to share his sub, then spring it on her once he has her agreement to start a TPE relationship. Or He knows he will demand a heavy service oriented slant to his TPE dynamic, yet his sub has no interest in making that a huge part of her life. In the long run, it will be a rocky transition, and the minute the sub has to say 'No' to her Dom, the relationship is unraveling.
So to recap, a TPE can be a very fulfilling dynamic, I came out of my relationship a much stronger person than I went in. I was pushed, focused, challenged, loved, nurtured, and I trusted my Master with every fiber of my being. I did things I didn't want to do at the time, but I never felt like I didn't like myself afterwards. I grew as a person, and experienced amazing things. And I feel it worked between us because on a fundamental level, our needs matched. And He took the time to learn me and only had my best interests at heart.
So to answer the question, "Is this just how these relationships work?" They are all different, you have to figure out how your relationship will work, but it has to make you both happy. So needs have to be met on both sides, and you start by learning each other and being completely open and honest about what you want and expect.