- Allow up-strumming always, so the bidirectional strumming is easier
I tend to strum down alot and just hit a few strings on the way up (when playing an actual guitar) so that's why I made it work that way, but enough people have commented that I will change it.
- Spread playback over at least two channels, so that the last chord doesn't break up when changing chords
I wanted to simulate a real guitar so it doesn't make sense to have multiple channels. When you change chords I mute the strings slightly and set them to open for a fraction of a second but it still needs a bit of work to sound natural.
- Consider multikey "gestures". So we can configure something like:
- Additionally pressed Up and Down arrows modify chord type (maybe betwen maj and min)
- Additionally pressed Keypad-0 pitches the chord up by an octave (or quinte or whatever)
- Additionally pressed CTRL damps the tone
Yeah I could have expression keys to modify the chord, good idea. I was actually thinking about a modifer key to switch to power chord versions.
- Or using the first 4 numbers only, but in binary encoding



to select 64 combinations of chords and chord types
Don't you mean 16 combinations (2^4)? The guitar hero controller has 5 buttons so you can get 32 chords without paging them (more than many guitarists know I'd wager).
- Other switchable effects could be half strumming speed, arpeggio ...
Once again, great ideas.
- Consider a midi-out to allow us to wire gtr or guitar rig

Could do but I am already spending far too much time away from games on this.
If you will ever release this source, let me know

Will do, I pretty much always release source if enough people request it. The only reason I don't initially is the time it takes to clean-up and package it.