The mutable Tsquare to Venus-Mercury and the cardinal Tsquare to Saturn are related by a quincux (inconjunct) between mutable Mars and Cardinal Uranus. Quincuxes are very irritating or motivating, whether they are bugging or or stimulating you at the time.
Quincunxes are one aspect I hadn't gotten around to doing much with yet, and I'm still trying to understand squares, but getting there. So, as I understand it... quincunxes are parts of life or the psyche that feel incompatible and have to be compartmentalized in the mind, while squares are differing desires that might build on each other, although with friction between them, which might slow down or hinder one or more of the planetary messages involved, or might create just enough spark to keep it going... am I correct?
And then T-squares also include oppositions, and oppositions are opposite desires that could be met with a compromise, such as one weekend I go out and party heavily and have a good time and another weekend I stay home alone and enjoy the solitude. (Not that I personally go to those extremes--if I do go out and enjoy a party, it's a mellow party, and I can't stay home all alone for a whole weekend without going crazy--that's just an example.)
Analyze the Tsquares one at a time. The mutable T is softened by two sextiles, to Saturn and to Pluto. I consider that is gravitas that keeps you from flying off the handle.
The general sense I get from my birth chart--and it also makes sense if I look at my own personality in this light--is that I have lots of impulsivity circuits fired up but then checked by something else. The result is that I am not a very impulsive person, but I would be if not for those checks and balances.
The Cardinal T is softened by two things as well, the Mars-Saturn harmony and the fire trine you originally asked about. I think it is fortunate to have a fire trine as a background stability to your chart. Grand trines are naturally stable, like having a kettle continually on simmer in your hearth. Sun and moon trined is already a fine situation to counter any disruptions you encounter in the operation of your Tsquare 'dynamos'.
I hadn't thought about it before, but Mars is in sextile to Saturn! And Saturn bears some exploration in and of itself. It's the ruler of my ascendant, so would be the ruler of my chart, but it's in its fall sign, and it makes those squares, so I am interested in what it's actually doing for me (or to me?).
I like that image of a kettle continually on simmer. I have looked at my sun/moon trine in this light: with the sun in the eighth house and the moon in the twelfth house, and the sun in the sign of ultimate personality development and the moon in the sign of growth, learning, and expansion, it seems that what my personality would want and what my deepest desires would be equate to learning, growing, and deeply transformative and transcendent experiences... and indeed, that is what I'm constantly seeking out. Many of those experiences have some relationship to healing, as well... perhaps that speaks to the Jupiter/Chiron conjunction?