Taken one at a time :)
Venus oppose Venus in synastry can indicate that the two individuals will have quite different tastes and values. It can be a matter of coming from very different backgrounds , having different ideas of what is enjoyable, or even the way that you express love might be different. Couples who have this aspect typically need time to figure out how to please each other and appreciate the other's way of expressing love/romance. DH and I have this one : He has Venus in Libra and I have Venus in Aries. We have been married a looong time and are happy but we do have pretty different tastes and ways of expressing love. Venus in Libra likes cards, romantic dinners, etc. My Venus in Aries thinks it's romantic to take a sudden road trip and send a "love ya" text. Also with this aspect be careful of arguments over money.
Mars trine Saturn is actually a pretty decent aspect in a synastry chart. You will have an appreciation of the consistency the Saturn person brings to your life in general. This aspect is also a stabilizing one, and brings some groundedness to the union. The aspect is a positive one for lasting attraction after the initial flash in the pan. Mars/Saturn aspects can be tricky so if you have to have one in a synastry chart then this is the best one to have.
Ascendant trine Moon-This one is also a beneficial aspect. It indicates that you will be "in tune" with her feelings. Emotional expression should come fairly easily between you and will feel comfortable in each other's company.
Mercury trine Venus- Generally there will be easy communications between you two and this aspect indicates she may spur your interest in the arts, design, or other similar pursuits.
Mercury trine Mars- This a fun aspect and indicates that the relationship will be intellectually stimulating. It can indicate that the Mars person (her) will help spur you on to higher achievements. Also indicates lively discussion and debates. DH and I have this and I love this aspect
Mars opposite Neptune- It is important to handle any disappointments in a way that keeps the Neptune person grounded in reality and doesn't allow them to play victim. The Neptune person can blow hot and cold and the Mars person can end up over-idealizing them. On the positive side, the Mars person can spur the Neptune person into taking some of their dreams/ideas and turning them into a more realistic form.
Hope that helps a bit more.