Hi arbisley,
On the number of pieces posted in a short amount of time, the recording were done over a period of years, not all at once.

Thanks a lot for listening to so many of them. I really appreciate it!
On the Schubert Impromptus, I only studied the two I posted here, Op. 90, No. 1 in C and the other opus continue four impromtus as well, Op. 142, No. 2 in A flat.
I assume you're referring to No. 3 from Op. 90 in G flat. Again, I probably have just cursory ideas, having not studied it. But here are some thoughts anyway:
Above all, this piece demands attention to the melodic line which is cantabile or bel canto. So shape the phases and longer lines accordingly. Sense of direction is important in Schubert. As the RH is effecting a careful legato touch to support the cantabile melody, there is also accompaniment within the RH. The LH is primarily, but not completely, harmonic in nature. So this piece is really composed in layers. You have the melody in the foreground, sextuplet figuration in the same hand that needs to be like a very serene, rippling "lake effect" which MUST be kept in the background. You also need to strive for perfect evenness in executing those sextuplets, which all begin with a rest. And finally the bass which is largely harmonic, requires proper balancing the two hands. So you need to think of this piece as being constructed like a sandwich with three layers in which you will carefully layer the dyanmics. I would certainly highlight the melody, then, within proper balance, give the LH harmonies second place, and the on-going filagree least emphasis as distant background.
Note that the dynamic through much of the score is pp and sometimes ppp. It's not easy to play an entire piece that quietly, except for a sforzando here or there. Watch the dynamic markings like a hawk, including the cresc.-decresc. markings. This will bring about needed differentiation in volume and mood. Doing due diligence with this shading will enable you to create more variety to keep your listeners from dozing off in the quietude!
Notice too there are some short scalar passages. For example, look at measure 3 in the RH. Scales have a special place in music, so you need to bring them out--but not in an exaggerated way. Rather, do it with clarity of touch always within the legato framework. These can also occur in the LH. Regarding the left hand double-note chords, I would usually voice the bottoms. But look at measure 4 in the LH half note chords. There I would voice the upper notes, since they're scalar, while the lower notes are performing only a harmonic function.
Measure 19, LH. At the end of the trill, smoothly blend it into the two-note appogiatura and then into the downbeat of 20. Start the trill on the lower note, as it is more customary practice for the period.
Without having played the piece, it's hard for me to comment on pedaling. Note that Schubert wrote ONE "Ped." marking at the very beginning of the piece, as if to give the performer permission, or maybe even full discretion to use it. You can group same harmonic passages in a pedal, changing it as harmonies change. Also you can use it to etch out the cantabile as needed. In 7 you have scalar passing tones, so that calls for changes on the quarter notes there. Most of the notation is midrange, or in the tenor and low treble, discounting the bass. The very quiet dynamic will enable you to get away with more pedal, but not as much as if there was more music in the higher treble. So you ear has to be the guide to ensure than your playing of this is clean where it needs to be. In difficult spots, you can experiment with half pedals and lifting the pedal to half, or quarter level or fully to effectively clear any possibility of clashes. Schubert has pretty much left you on your own in that regard.
Well, I don't know if that helps, but good luck to you in learning this piece! It has a nice sound to it, and I'm sure you'll enjoy doing it.
Don't overlook the fermatas in 54.
Looking ahead to 74, you have a long cresc. there. Spend it wisely! 76 is actually ffz at the top of the cresc. Another one at 81.
Throughout the melodic line there are some forzando accents. The first ones are at 25. You might want to take a pencil and color those in as better visual cues so as not to miss them. Notice in those two instances, they are over whole notes. The purpose there is to help combat tone decay, thereby sustaining sound for the full value of the notes.
David