Mars Square Saturn means that there is a risk that the native is hateful and bitter, with a very irritable temper, sometimes it indicates the opposite - a person lethargic without motivation or drive. But usually it suggests a irritable temperament and a contempt for weaknesses in others. Hitler had this aspect, and I have seen it in Three people I knew IRL - they all had this rough disposition, very angry and irritable, who hated the weaknesses of others. I have seen a hatemonger with this aspect too, a religious one. This aspect can often mean cowardice.
Venus/Saturn gives sorrow in love, trouble in affections, sometimes perversity, but it gets better with age.
Venus/Uranus makes the native eiither attract Uranian, unstable partners, or he is one himself, or he wants a relationship, yet wants to be free at the same time. Perhaps there is some obstacle in the way of him being able to truly connect to Another. Can sometimes indicate peversity as well, if afflicted.