Do something ala

g = someotherbuffer.g2;
g.begin();
g.pipeline = pipeline1;
Scaler.scale(backbuffer, framebuffer, System.screenRotation);
g.end();

g = framebuffer.g2;
g.begin();
g.pipeline = pipeline2;
Scaler.scale(someotherbuffer, framebuffer, System.screenRotation);
g.end();

You can call addAssets('whatever', { readable: true }) in your khafile I think.

Get an up to date version of Kha from GitHub and point Kode Studio to it (via the khaPath option in the settings). The latest Kode Studio version is still from before the release of VS2017.

No idea. Ask Lubos - if you bought Armory I'm sure he'll be glad to help.

Maybe because your project is missing a khafile?

Float32Array.hx is right here for the Windows target: https://github.com/Kode/Kha/tree/master/Backends/Kore/kha/arrays
Don't know about build.bat, haven't used that in a while. Try to use the usual method (node Kha/make windows) instead.

Debugging projects in Krom does not yet work.
There is nothing special at all to using multiple render targets, just try it and ask more specific questions if you run into trouble.

I think we can't do that yet - please create an issue on github.

Does that Krom error happen on any project? What macOS version is that? Is that using the integrated Kha version?
For multiple filters, switch between multiple render targets.

Shader debugging - not yet. Krom - yes but try to use Kode Studio's integrated version of Kha instead of a newer git version (because there were API changes).