The Mars sphere is a vibrational universe that makes many magicians uncomfortable, and not just because Mars is called the "Lesser Malefic" in traditional astrology. Franz Bardon, in his second book which is titled "The Practice of Magical Evocation", applies a special treatment to his writings on the Mars sphere, giving only the names and zodiac degrees of the positive spirits, holding back their descriptions and refusing to say anything about the negative spirits.
It is a bit different with the Venus sphere and other spheres, for example the Moon sphere; these are usually not considered as dangerous. Franz Bardon to my knowledge is the only author that explicitly mentions the dangers of Venus spirits. He also warns his readers in a general way against the negative spirits that are part of every zone. To me, the Venus sphere and the other spheres should be approached with the same caution given to the Mars sphere. Moon spirits can cause escapism, addiction and an overly dreamy demeanor. And of course the spirits of the Earth Zone are the conduits through which all spherical influences must eventually come through.
So every sphere has its own traps and dangers, since a sphere is infinite and its consciousness vibrations mix with all other vibrations in existence, regardless of man-made morals. To the pure everything is pure, but the trappings of human consciousness can easily create suffering when faced with the influence of demanding spirits and the consequences brought about by that influence. As a simple example, spirits of strong plants, when ingested, can make a man addicted. This addiction might destroy the mundane worker/sheep life of the person, causing them suffering. Or it might serve as the cause for suicide, or death by accident. Mercurial spirits can cause schizophrenia, an overload of psychic impressions.
That being said, what Divine Providence ordains reigns supreme, and the sphere-walker must face these dangers instead of shying away from them. How can we attain mastery over something that we refuse to become acquainted with? Of course I presume here that this mastery has not been attained by us yet, so if we already integrated something in a past life, there is no need for us to confront it again.
The Venus and Mars spheres are very interesting, because they are closely related to passion and emotion. Whereas the Venus principle will without fail imbue the practitioner with increased, sometimes fabulous, powers of attraction, the Mars principle will seek challenges, battles, and constant self-improvement. But you might become overwhelmed by the sweet, sweet Venus spirits that come with this attraction, refusing to make room in your life and consciousness for anything else besides hovering in cross-eyed bliss at the "sight" of Venereal spirits of beauty. Or, in the case of Mars, your next challenge might be too big for you. "Maybe driving this 600 HP car was not that good of an idea after all", the Mars-influenced person dying in the car wreck might be considering.
However, persistently working with these two forces, and working hard at bringing them to an equilibrium and keeping them in that state eventually brings about a certain fundamental degree of mastery over both of them. The feminine and masculine polarities become balanced, orbiting a gravitational center of concentrated consciousness at the point where the individual's ideal state of equilibrium of these forces was built up by repeated focus. This decreases the potential of these forces bringing about an imbalance in the magician's life. For example, whereas a person favoring Mars strongly over Venus might become enamored with guns might bring war to their country, the Venus principle in a balanced person will tend to prevent that, by virtue of its desire for peace and harmony, and its abhorrence of everything truly violent. This of course only holds true if your heart is not dark. A person walking a negative evolutionary path will achieve the opposite mastery, seeing sublime beauty in violence and war (a negative trait of Venus in Scorpio) and a strong desire along with the means to perpetrate it.
For both men and women, it is of great benefit to work with the Mars and Venus spheres, resulting in perfection and a balancing of their own masculine and feminine essences, bringing both passion and love to their relationships.
Any thoughts are welcome. A whole book could be written about this topic.