More Tricks:
If your high G# (concert C#) is low or unfocused, try playing it with the second octave key. Although it will raise the pitch and add stability, it might also add noise.
If your high B flat (concert E flat) is low or lacks focus, try adding the 4th finger of the right hand.
If your low E (concert A) is sharp, weak and/or “gurgles”, try lining the top part of the tone hole with nail polish. Another solution would be adding a small piece of adhesive tape, which can be easily removed.
You can play high C# (concert F#) and D (concert G) with the F key added and it will help the tone and pitch.
Learn the “Rosenblatt” high C# and D which are my favorites.
Learn the “Kraus” high C# for added potency and different color.
If you have trouble playing high C (concert F), change your 2nd octave vent to a Loree "DM" vent and enlarge it by 2 drill sizes: .032 #67 or .033 #66.
If you still have trouble playing high C consider thinning the tip on the reed a little more.