Congrats on your offer. If I am reading it correctly, with 2 years of Experience, you are still quite young. Take it as a compliment
Your main reasons for a ding at McCombs and Rice are likely the experience and your GPA is a red flag. Anything less than 3 is considered a "low" GPA and 2.7 is definitely low by the top 20 standards . It is not a life-long problem that will keep you from everywhere but it is something that you need to be aware of, and as you said, nothing can be done, so focus on the items in your control.
It is up to you at this point what you want to do. UT Dallas is a pretty small school with only 50-60 people in the class, 43% international applicants. You will be pretty tight with your classmates. Check out the admitted students weekend and see how it feels if you have not already.
There are 2 things:
1) Are you ready for the MBA and is it a good time for you to get one? Job market is doing really well, you are doing well at work, what is pushing you to get an MBA? Do you have enough experience to jump 2 levels and land a Director role? My guess it will be tough just due to age but it all depends on how you sell yourself and your confidence level. If you are ready, then go.
2) You can definitely do as well next year and potentially better applying in earlier rounds but you need to fix some things. If you are unwilling to fix them, then go for an MBA now. Your GMAT is surprisingly low on the quant side.... Low quant score from a finance person indicates almost laziness of sorts.... If you can prop it up and get into the 750+ land go compensate for your GPA, that would be fantastic! That would even help with recruiting and definitely scholarship money in schools in the 20-40 band (Rice included in there). By the time you apply, your essays and stories should get more seasoned and get better. FYI - Average McCombs work experience at matriculation is 66 months....
https://gmatclub.com/forum/mccombs-203/stats.html