I've done some research on the P composite chart coinciding with the date a couple met, and I've found some pretty significant conjunctions from the individual natal charts to the P composite chart. The first thing I would say you should look at is if the P conjunctions from the composite chart shows significant synastry aspects between the N charts alone so the aspects would have significant value to the meaning of the relationship and the couple. For example, Since the P Sun and Venus are making a conjunction to your natal ASC, does the other person have a natal conjunction to the P Sun and Venus as well? What composite house does this occur in? Since the aspect is of prime importance to you, perhaps should see what house it affects you in personally. This would be how the conjunction of energies would unfold into your life. A composite chart that doesn't show conjunctions to the individuals natal chart will be of little importance to the person, so check that out as well.
M H conjunct your natal Venus. This point is public standing and role in the world, maybe the relationship is destined to expose you to a new reality in this realm. And falling in love may be the reason why.
P Asc conjunct her Asc means that the relationship was given an opportunity to develop significantly when you met. Supposedly, people who later become spouses usually meet when there are exact P conjunctions and oppositions to either the natal chart, or both the P charts.
A word of advice: I wouldn't use anything but conjunctions and oppositions when comparing P to natal, or P chart to P chart. These are the most meaningful. As far as the asteroids go, I have no idea about them, I only like the vertex.
I met a very significant person, perhaps the love of my life when the P composite sun was conjunct his natal Venus and Mars. Since he has this natal aspect in conjunction to my natal S Node, It is of prime importance. So as you can see the (energy) of our relationship coincided with this significant syanstry aspect we have because our meeting was due.. A progressed composite chart is just the relationship as it moves through time. Another important thing about when we met was that the exact day transit Sun, Mercury, Venus, Saturn, were at 24 Leo, which was in conjunction to our composite sun, which also occurred in his natal fifth house. Let's just say that this love is not exactly light. These are just a few of the conjunctions that occurred between the P, Draconic, Davison, Tertiary, and also the Solar Return of that year for us.
There a multitude of different ways we can discover why people meet and fall in love. You may want to check out the solar eclipses and see if any fall on the composite chart or you individual natal charts, as well as the P charts. If so, I'd say you have a pretty important relationship on your hands. Remember.. only conjunctions and oppositions though.
If you want, I can look at it for you.