Distortion is quite easy! Just add a distortion pattern to UV coordinates and plug it into the UV input of a texture, and you just made distortion
Similar to this:
Shader Forge doesn’t generate deferred passes at all at the moment, which means that when you’re in deferred rendering, SF shaders will be forward rendered, this breaks, as far as I know, translucency, tessellation, and probably a few other things that I haven’t noticed yet.
Deferred is a huge topic and a massive feature.
It would take a lot of work to get it up and running smoothly with SF, because deferred has a completely different shader pipeline, but it is something I will look into after the 1.0 release!