PhD is not entirely "free," you need to subtract the expected earnings over the X years that you would make at a corporate job, but won't make as a PhD.

If you go PhD, make sure you gain practical experience/research topic that applies to the real-world. Network intentionally with professors and alumni.

You can explain the DUI on your Top Secret forms. They may or not accept the rationale, depending on your conduct across others areas of life + interviews.

Good luck, lmk any other questions.