Hey! I think having research experience is great, it definitely will not hurt your chances of getting in. I know a few applicants who had more research than clinical experience. That being said, you want to make sure you have clinical experience too, whether that come from shadowing veterinarians, or working at a clinic, etc. For dual degree applications/interviews, your research might be a bit more important than the clinical work (ie as long as you meet the required/average number of clinical/animal hours for the veterinary school, that should be fine).
For me personally, I had about 800ish lab hours (maybe?) and over 2000 clinical hours.... I worked full-time for the better part of a few years, and took a year off while applying, so that helped increase my hours. For you, I think your 500 hours is great,
given the quality (versus quantity) of those hours. If you were able to build meaningful relationships with a vet(s), and learn some relevant clinical skills, then that should be fine for most schools. In other words,I didn't need all of those hours per-say, (yet I did enjoy going to work!), but what was important was that my references were able to speak highly of my experiences at lab/clinics. Schools care more about what you learned versus how many hours you racked up
Just make sure when you apply, you have at least one reference who is a DVM, which is required for most schools (ie you would have had to have some sort of clinical/veterinary experience in order to know a vet well?)
Perhaps keep up a little bit of clinical work/experience/animal care, to show a sustained interest in vet med as you are applying, and then keep doing lab work? Also, your projects sound awesome, I'm leaning towards the cell/molecular biology end with my work too!
What type of projects do you do in a biophotonics lab, out of curiosity?
What also looks great if you are considering a career in veterinary research/thinking of applying dual degree is some teaching experience. Whether that is tutoring, test prep, an undergraduate TA, helping professors, etc, a large part of a research career, especially if you want to work at a university (as an investigator or a clinician) probably will involve some teaching responsibilities. I know when I applied, that helped my application. The subject doesn't matter, but I guess science doesn't hurt! I wrote in my personal statement how teaching and tutoring science made me a more effective communicator- in writing, speaking, and listening. These skills are valuable to have as a clinician, scientist, or any professional, so teaching can never hurt an application! (plus, you learn so much more about a subject when you have to explain it to people, which is really cool).