There's no evidence we are in the new Satya yuga.
There were lots of points in your post that I see have been answered, thus it may be we just have not yet seen the evidence, when it has been made available.
I sèe Jims post shows people are looking for the answer to this part of your post;
While all religions may be valid, and lead to an ultimate truth, they are valid for their followers, not everyone else... there is no oneness and unity of religions.
I see they do all lead to a single source, many others are finding this also.
Regards Tony