I don't think you can upload your own impulses to a Palmer.
And why would you even want to? Just go from the fx-loop of your amp (cab connected) to your interface and use impulses in your DAW (with Boogex, SIR etc.).
yes you can...... turn off the volume filter and the hi-cut off it should be fine for impulses with this setting or use the palmer only as a load and use your fx-loop