Now it looks like you are over-extruding. Here are the settings to check:
- Filament Diameter (measure your filament at several points, checking each point twice at 90 degrees to see if it's oval, then take an overall average)
- Extrusion Multiplier (probably should be 1.0; it's pretty sensitive to small changes)
- Extrusion Calibration (with geared extruders you will be in the ballpark of 600; with direct-drive you will be in the ballpark of 100 - but you really need to measure the Extruder calibration yourself. Unlike the belts and threaded rods, individual extruders are not all exactly alike)
- Nozzle Size (probably should be 0.4mm; you would know if you have swapped it for a different nozzle)
Also check to see if you are overriding any of Slic3r's default calculated settings like trace width. Leaving these at 0 allows Slic3r to calculate your best setting.
The pause at the corners may be due to "retract" settings. You need different setting here depending on the type of plastic you are using, but as a general principle, the more motions you ask the printer to do at each layer change the longer it takes. If the filament you are using tends to "ooze" then even though you are asking it to retract you still can end up with a bit of a blob due to ooze.