Hello..I'm also in the process of the studying the Waldstein.
Um...as for the glissandos, I know what you are referring to, as I saw a video of Amir Katz (11th Van Cliburn comp.) play it at the preliminaries and from what I saw, he played the octave and then dragged them downward, (as if it were nothing!) Honestly, I don't know how he did it...
Also, with the melody in the RH, you don't trill at the same time, but just play it out with the 5th finger..as soon as you play the melody note, you continue trilling....it is happening so fast that the ear can't tell that you stopped trilling for a fast second.
Hope this helps