@ Serpentine,
whew!!!
As far as astrological concerns are to be addressed, you can wear Ruby in silver, as its significator Sun, is the friend of silver’s significator – Moon. The results may be very slightly less or delayed, thats all, nothing bad is gonna happen.
Regarding your other queries, they best be communicated with a professional gemologist or crystal therapist and chinese experts (yin-yang hand query).
There are many ideologies in wearing gems and rings.
1. you can wear on the active hand as the gems will be more communicative with the body through the part of the brain (opposite side of the hand)
2. Religious beliefs do not advise wearing gems on the left hand as it is used frequently for typical activities of cleaning certain body parts.
3. Comfort levels also determine
4. If you wish to increase the yin properties of the gem then wear on the yin hand or else the yang.
There will be many proponents as there is never a single solution, my advise, follow your own spiritual inner guidance, as you know a lot in spirituality and have been taught too.
The Zen philosophy of following the inner self will work best here, for you, especially.
Wishing you good luck, may God GUIDE you and over all,
CHEERS