What about Brown specifically appeals to you?
You have great credentials and an interesting background. Your viability as a candidate would in large part be a function of your ability to communicate what about Brown (or any school) is of interest, how you would contribute to the Brown community and how you could leverage Brown’s open curriculum.
FYI I note your interest in a liberal arts atmosphere and flexibility to study various subjects but the devil is in the details.
I don’t think anyone can accurately chance you without understanding what is important to you and or your ability to convey the sort of passion that Brown (and other similar schools) seek in applicants.
Happy to try and help and either way good luck!!
Lastly if Brown does turn out to be your ultimate reach, make sure to run the numbers and discuss with your family if it is affordable before applying.