Knowing nothing about Theo. Chem., I am hesitant to say much about what you would be missing.
One thing that strikes me, is your statement that you will have "gained practical experience in programming, data analysis, and Linux administration." Is that all you will have gained from your degree? In Hep-Th, you will also gain those skills. Where are recent grads from your school in Hep-Th working? Is that more desirable than your Chem-Th prospects?
I don't blame you about the job part. It can be very frustrating spending 4+ years doing all this extra schooling, getting out making less than all your friends with BS's, working 4 more years at low pay in a postdoc, etc. I should know, I am doing it now...
Anyways, you will have the added annoyance of what academics like to call the 'two-body' problem. If your husband is also in academics it will be very difficult for both of you to get good jobs in the same place. Just the nature of the beast.
Just something to consider.
On this forum you will hear from people who are unemployed hep-th grads, trying with great difficulty to find employment, to people telling you there is no problem finding jobs with a degree in hep-th. So, take it all with a grain of salt (and maybe some tequila too!)
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