Wow, guys... I was just asking for opinions! (as a "newbie" in the forum I could not make more posts, so you kept coming...

)
I have done ALL of the above. Yes, there are solutions.
But, my point is there is no specific product out there to solve all the parts of my initial question.
Yes, I can wear other clothes, but I don't want to change my clothes to be able to store my keys
Yes, I can store in socks, tights, etc, but it will bother me
Yes, I can hide my keys away. This requires a suburban environment (rocks, etc...) and lack of peace of mind while riding (if you disagree, ask those that take their keys with them)
Yes, I can definitely put them in another bag that I already have but it might make noise
For those that thought I would stay home preferring not to choose any of the above, well you misunderstood me.
So far, the SMALL seat bag solution sounds the best, so you can ride fast, too, without affecting the weight, but I should stuff something else there to keep the keys silent.