All I can say is, "Welcome to the Cardinal Square Club!"
Seriously, though, you're in an astrological situation very similar to my own with various inner planets in your Cancer stellium squaring various outer planets in your Libra stellium. Mars is more of a social planet than an outer planet, but you get the idea.
Ironically, though, all of my cardinal squares involve planets in Aries and Capricorn, while all of your cardinal squares involve planets in Cancer and Libra. Together, we cover the entire cardinal cross!
Now, back to your chart:
I'd probably still consider Saturn to be in the twelfth house due to its wide orb to the Ascendant, but Pluto is so close to your Ascendant that it's practically fused to it! Similarly, Mars is within three degrees of the Ascendant, so I would also consider it to be under the influence of the first house although technically it is located in the twelfth.
Your natal Sun in Cancer is in a similar situation; I'd personally consider it to be in the tenth house since it is only slightly more than three degrees away from the Midheaven, which is one of the most powerful angles in the chart. The rest of the planets are firmly within the ninth house, though.
Although you can look at these two stelliums as squaring each other, I would also look at the planets separately in order to determine which aspects are the tightest and therefore the most powerful.
Both the Sun and Pluto are conjunct your natal angles, and although the Sun is separating from the aspect (i.e. decreasing in power), the orb is less than three degrees, which is tight. Therefore, I would study this aspect first because it is bound to have a profound affect upon you.
Mercury is relatively close to the Sun, so it is still within orb of the square aspect to Pluto, but I would first look at the aspect Mercury is making to Mars. Unlike the Sun, which was separating from Pluto, Mercury is applying (i.e. increasing in power) towards a square aspect with Mars and then Pluto. The orb of this first aspect is less than two degrees, so it too is important, as is the applying aspect Mercury is making to Pluto. I almost forgot to mention that Mercury is also separating from a square aspect with Saturn. Explore interpretations for all of these.
Now we've got that beautiful, extremely-tight conjunction between the Moon--already in the sign of its rulership, Cancer--conjunct your North Node. This is a double emphasis upon the importance of developing positive Cancerian traits in this lifetime. Before I become too enthralled with this, notice that the Moon is applying towards Saturn. I wouldn't consider the Moon to be in orb of Mars and Pluto, but its square aspect to Saturn is still important--particularly since the Moon is in the sign of its rulership and Saturn is in the sign of its exaltation and the house of its joy.
Another theme has just emerged; your natal Jupiter is in the first house, conjunct the Ascendant with an orb of almost exactly six degrees. Although your natal Pluto and Mars make tighter conjunctions to the Ascendant, they do so from the twelfth house side, so they are not completely visible--unlike Jupiter. As you correctly observed, you have a stellium of planets in the ninth house. The cusp of this house in your natal chart is Gemini, so Mercury rules your ninth house cusp...but let's ignore this for a moment and use the astrological alphabet, which I once held in disfavor but am beginning to find use and meaning in once again. Although signs are not necessarily the same influences as houses, and some may regard it as a coincidence that there are twelve signs as well as twelve houses, I no longer believe in coincidences; everything has meaning. Using this system, the ninth house is associated with Sagittarius and Jupiter, so this is another theme that is highlight in your chart, particularly since your North Node is located here.
The ninth house is typically associated with philosophy, travel, and higher learning, and I recommend that you research it further. The fun in astrology is not having others give their opinions about your chart, although this can certainly be helpful; the fun is in discovering answers for yourself. This may be the independent Aries in me talking, though!
I wish you the best of luck on your journey.
Arian Maverick