You identified some wise lessons from the experience, Dawn. Yet I do hope you'll try another escape room sometime (maybe even with different teammates?). I absolutely love escape rooms and have done them with co-workers and my husband and daughters.
I think the key is that you have to know who the "competitive" ones are ahead of time so you can make sure you're especially aware of them. I also think the emphasis needs to be on communication--can we delegate subsets of the team to work on different puzzles so we're not all crowded around the same puzzle at the same time? It also helps to know what your own strengths and weaknesses are.
Thanks for sharing your experience!