There isn't any provision within this mod to do either of those things, though I suppose I could add something.
All of the recipes for vehicles are constructed on the fly, so that the mod can support mod-added vehicles.
I think the easiest way to do so, would be to hide the recipes in question.
data.raw.recipe['recipe-name'].hidden = true
The main reason for having the electrical -> vanilla conversion is to support mods where the base vehicle can be upgraded; vehicle mk1 -> electric vehicle mk1 -> vehicle mk 1 -> vehicle mk2 -> electric vehicle mk2, ...
If I recall correctly, the recipe for the power plant should be in data.lua.
I can add a setting to remove the electric -> vanilla conversion easily enough, though I'm not quite sure why you'd want to remove the power plant?