Interesting you are dating a Gemini Sun and Mars, with your dislike of Geminis in that one thread.
What I see is that this is a relationship that’s good for friendship, and it may last a long while on that count. There’s not too much conflict or warning signals here. The main problem I see is that loving feelings are missing. I am not saying it’s not there per se, and I know you like to play the devil’s advocate. But you guys would both, easily have stronger, loving feelings and chemistry with someone else. And at the end of the day, genuine love and affection is a huge part of relationship success.
Indicator patterns are: Your Venus negatively aspects his Uranus. His Venus makes no contact to your AC or Sun. Composite Venus sits in the 6th house with almost no aspect, not strongly placed. It has a sextile to moon ruling affection and home, but its not otherwise strong enough for a love relationship.
A second problem and many would disagree with me, is that Chiron aspects your NN almost exactly. He will bring you pain. I didn’t take too close a look at mitigating factors since there were no tables. But in my experience, it eventually plays out. The questions is how many years, and when? Perhaps you're willing to deal with it as your Venus is close by. Yet, one can't deny it's much better if you have a more positive connection to the NN, than a controversial, loaded connection.
The main attraction for him is that he needs a stable, grounded, down to earth woman, or maternal figure. This is exemplified by his Moon Saturn conjunction in Taurus aspecting your Sun, Mercury, DC, Mars and very loosely aspecting Saturn and your AC. It adds a lot of stability here as he is extremely comfortable with you, and also very supportive of you. With his involvement in your life, I also surmise he helps you deal with that Mars Saturn opposition of yours.
But does comfort translate into love? That’s up to you to decide.
Lastly, when analyzing a romantic relationship its always best to start from the basis of the Natal, not synastry. Chemistry is a poor indicator of health. As you can have chemistry with people of all walks of life, the highest quality to the very lowest denominator, but it does not mean its always wise.