How can I create this effect? The edge 3D function always comes out corrupted and using blurs isn't always effective because blurs are round. How can I create a simple bevel effect like Photoshop can create?

You need to use blur, keep the stroke color darker than fill color. Then clip the blurred object with a duplicate of itself only without blur. This way you get shadow that is equal everywhere along the edge, there is no specific direction where the light is coming from.

To get a direction you need to play more with shadows and/or highlights, inset/outset them and move in the direction of the light source...

I found the edge 3D working nicely, you just have to pinpoint the right settings for a particular object.

The easiest way to bevel is to apply a bevel filter, but you can only find them in pre0.47 version.

Yeah, clipping does work. It's a little harder for more complex shapes though. I managed to pull off a bevel using only small blurs, but for the next part, it needs to be very precise. Can the clipping step be more precise?