The mutual receptions are:
Sun in Aquarius and Saturn in Aries: Sun is exalted in Aries and Saturn is domiciled in Aquarius
Yes, this is mixed mutual reception, however by detriment or debility so not really a positive thing. In your chart Sun is separating from a sextile to Saturn so it isn't as bad as it could be were the Sun to be applying to Saturn, but what you have here is a case of a detrimented Sun relying on and in the home of his sworn enemy (Saturn) who is in turn in fall in the place where the Sun is exalted. In this case, hands down, Sun wins.
Mars in Libra and Saturn in Aries: Mars is domiciled in Aries and Saturn is exalted in Libra
Another case of mixed mr.
Venus in Capricorn, Mars in Libra, and Saturn in Aries: This is the 3-way domicile mutual reception that I was wondering about
Remember that at it's base, reception is about allowing. So which planet is allowing another, and to what extent. Venus in Mars exaltion, Mars allows, same for Mars in Libra--Venus alows Mars. The difference here isn't really about the reception but rather about the position. What is a debilitated Mars capable of, that Venus is going to allow him to do?
Venus is in turn received by a heavily detrimented Saturn, so while she's in his his and he's going to allow her to do stuff, she still has to follow his rules. Or, in the case of your chart possibly not, because Venus is in her own bounds, interpreted as Venus being bound by her own terms.
It really comes down to taking each planet apart and looking at it in relation to every other planet in the chart.
Also, Saturn appears to be a sort of secondary ruler of the fire triplicity according to this one thing I read, so maybe it's not peregrine either.
According to the Dorothean triplicities, Saturn is the participating ruler of the Fire triplicity. Basically, he rows when there is no wind (don't ask me to explain it, it would take more time than I have) but does not get dignity for being in the fire triplicity. Triplicity rulers have to follow sect (something Lilly doesn't allow for, btw). So if it is a diurnal chart Sun rules fire and gets dignity. Nocturnal, then Jupiter is the triplicity ruler. We don't consider them if otherwise.
I really need to learn how to use Astrodienst because I remember that you can change the house system, get rid of the outer planets/asteroids, add in various things such as the parts, and all sorts of other things but I don't remember how to do any of them.
Drop down arrows/boxes. Play with them. It's like riding a bicycle.