Are you certain about that power steering leak? It may be motor oil. Regarding that leak and most others; More often than not it is simply valve covers and or breather covers that weep and make their way down to the other areas. Have you resealed those before? I wouldn't tell your mechanic anything until you were certain where the leak was coming from. And you may choose to fix it yourself if it turns out to be an easy one. Perhaps spray down and clean thoroughly, then take for a good long run, and inspect again to find the source or sources. Are you leaking trans fluid? Have you done the transmission plug repair that Waldig did a D.I.Y. on? Pull that rubber weep/inspection cover off the bottom of trans. and rub your finger around in there. The noise is hard to tell. I'd guess exhaust or heat shield related. Does it go away at higher speeds or get progressively worse?