The Sun is still God in a chart whether you're reading a man or a woman's chart. True, a man may be more in touch with his Sun sign and less in touch with his Moon sign and vice versa for a woman but that doesn't make the Moon more powerful. Remember, astrology is a reflection of nature ... and the Sun is the center of our solar system -- the luminary around which other planets oribit. (The Moon orbits the Earth, which in turn orbits the Sun).
2nd Question: Yes, you could be compatible with the Gemini Sun/Scorpio Moon. Your Sun/Moon in fire/earth compliment his air/water combination nicely. Your guys' Mars are in the same sign and while your Venus's are in wildly different signs -- Sagittarius vs Cancer - this doesn't negate compatibility. It doesn't take every planet/sign combo to "match" with someone else's for there to be compatibility ... as long as there are some core connections, there's usually a chance. And if you're attracted to him, it seems nature would let you know there's a little something there. But it will take work like anything else.
Lastly, you really want to pay attention to that Capricorn on your descendant only if lasts for five degrees. That is the sign which has dominion over your 7th house -- even if it was only for one degree -- you'd be no less of a Capricorn descendant. Sure, someone who has a planet in Aquarius may seem more alluring by nature of the fact their planet falls in your Seventh, but that doesn't change the "reality" that you choose partners/conduct yourself in relationship with a Capricornian bias. I'm actually a little surprised you're attracted to Air signs...though that could be your Gemini Mars. And there is a theory that the Mars sign represents what women find attractive -- so witty, conversational, cerebral, youthful, etc. types could hold special allure. You're also a Sag Sun, so air signs would be natural partners. It also doesn't look like you have a lot of air in your chart (save for your Mars) so there could be an attractive, "balancing" affect that people with a strong air-sign influence have for you. So I guess I'm really not surprised :) Take care.
And agree with what Michelle says above ... there's so many theories in astrology, which it's why it's really important to observe your own experience and see what holds true for you. But yes, the Moon -- actually I would say for a man or a woman -- has more to do with that rich, emotional commitment and nurturing "necessary" in a marriage. Venus is about attraction for everyone ... but I think, so far as my experience is concerned, that lunar compatibility is important -- perhaps more important for the long-term than Venus (though it's nice to have both!)