I have to share something here... I do not have RSD, but I do have other pain issues.

Back when I was young (before I was 20), I met my then future husband at college. (we were actually matched by the first dating computer ever in my state in 1965!)

He was always kind and attentive even back then. And compared to other guys I had dated, and knew, he was certainly the exception! I didn't have any major medical issues back then, but he was still attentive. Now we have been married for almost 42 yrs, and his personality style, has become my life saver!
But he was kind and helpful when our son was born after 14 yrs of marriage, and he is kind to our pets as well. He has always accepted my "independence, my creative side, and my professional side".

With this new guy, take a look at how he treats service people, waitresses, sales clerks etc. If he is considerate with them too, that is a + in my book that he has kind traits. Kind to animals?
That is another. Sometimes young women find kind men "boring", unexciting. I personally loved it when I met my husband, as my Dad was anything but kind. My Dad wouldn't even stop the car so I could use a bathroom (I have a congenital GI defect that made that important now and then), but my husband, always found a way to get me to the bathroom when that problem manifested. It sounds corny, but that right there gave him a huge boost in my estimation of him as a potential partner in life!

But time will tell. We dated and were engaged for 3+ yrs before we got married. Time is a very good way to gauge people. I found out later, that my husband as child helped his mother, who was sadly an alcoholic. So he had "experience" with attending to people who may need help now and then.

I would think other warning signs would be, asking about your money situation, your potential inheritances, disappearing and reappearing and resenting questions, things like that.

I'd say if this new relationship is fun and rewarding for both of you at this early time, you should just enjoy that. When you get older you will look back on these nice times with great gratitude and nostalgia.