I can relate to you here very well. I was a pharmacologist (phd) with lots of lab experience before med school. I continue to focus my research on identifying important pathways and developing novel pharmaceuticals. To that end all of my med school research was directed by a surgical oncologist rather than a radiation oncologist because at my home institution our rad onc pi's were more clinically oriented. Like you, I picked rad onc because clinically it was the best of all worlds. You are technical, but not in the OR all the time, its out pt with good continuity, and finally as you said we have great toys.
A few points for you:
1) no phd = no problem for you. You can still do this career and get funded without a phd.
2) look for residencies at places that can support your research. Places like Duke, vandy, stanford, yale, uchicago, harvard, the places with good core facilities and established projects.
3) market yourself as who you are and what your interested in. You dont have to fit everything in your personal statement or research intentions to rad onc specifically. Cancer therapy is multimodal in almost all cases and as long as you are doing research to benefit your patient population thats fine. But you absolutely do need to be able to convince people why clinically rad onc is the only love you have4
4) be open to being more of a cooperative translational clinician. Im not saying can our dreams but due to a lot of forces in the land scape many rad oncs work very closely with basic scientists (and even have input into experimental design and direction) but dont actually have their own lab. This allows more clinical time and avoids some funding head aches. Be aware of this path and open to exploring it as you find your clinical identity. Also, there are more of these jobs available.
5) non rad onc research if high quality and clearly useful in helping you with your future career is very useful. If you have time to do something onc related great (and seriously think about doing it) but if not it wont be the end of the world. I had no rad onc research and did zero away rotations (wanted to, but had personal stuff come up) and did ad well as anyone because I had a solid plan programs liked.