I don't get why you claim to be a firefighter as being clinical. Why can't you say you were an EMT?
Your clinical experience seems limited. 30 hours of shadowing and no other hours working in a hospital, hospice, or clinic setting? Maybe being an EMT is clinical, but it doesn't overcome my perception. Not having a variety of clinical experiences, especially in hospital settings, puts your application at risk of getting screened out.
Non-clinical volunteering for literacy is nice, but it doesn't address more service orientation like food distribution, shelter volunteer, job/tax preparation, transportation services, or housing rehabilitation. If anything, it feels to me like it's just a natural extension of your humanities interests, so it could be construed as an academic endeavor, just as being a math/science tutor for similar children would be for a science major. That means with zero service orientation hours, you are at risk of being screened out at most schools.
Your activities during your gap year would be great (military... definitely counts towards the non-clinical volunteering service orientation bucket), but realize their full impact to help your application cannot be realized until next cycle (1 year later).