using your fff it slices just fine for me and look good in the preview. one thing i notice though is there is too much overhang with this model. first layer looks good but when it starts to print the perimeter on layer 2, the perimeter has almost nothing under it. that perimeter is printing over air. it didnt start to look good until i got the layer height down to .1mm. you might want to reduce the layer height to .1 and try again. also your nozzle is .4 and you have your extrusion width set to .4mm. this is a little too low. the extrusion width should be higher than your nozzle width. turn that on auto or set to an even .5mm. too low can cause spotty extrusion in high overhang or unsupported areas.
If you make the model solid you can specify 4-6 perimeters and 0% infill for stronger walls. As jimc said earlier, "advanced tab, turn on merge all outlines into a solid model. use zero top layers." This is different than vase mode, but accomplishes much the same thing (except the printing probably won't spiral, so quality may not be the same).