Hello; If your nozzle dia 0.4 your layer is good but bed leveling is important because x axis moves linear but your bed slope your part gets gaps. If your extrusion value is much and first layer height is high than other layer height, bed adhesion seem good but your part gonna get gaps. I prefer UBL for bed leveling. It crates your bed plate and saves. High temperature not good every time. If your printing speed slow and linear advance feature not active, there are lots of bubbles on your part surface. And your filament is too runny. Also it could be some gaps. There are little bit relationship between extrusion multipler,temperature and speed. And different brand's filament has different chemical and physical effects. Even different color. In this case, you should adhere to the manufacturer's recommendations.