okay so you've got a short bowden tube. Long slow retractions are always going to be an issue. Not sure why people recmmend them. to be honest.
As a general rule the faster you can retract the cleaner the print will be.
5mm is probably too long, certainly at 40mm. by the time it's pulled the filament in and pushed it back out, it'll have missed the start of the next printing section.
The general rule is make retractions as fast as you can. 60-70mms is my usual retraction speed - on all machines.
Also you want the shortest amount you can get away with. 2-3mm is what I usually aim for.

Not a clue what: retraction count 90 - means.

slicer wise - it is worth buying simplify3d. It's probably the only software I've paid for in the last 10 years, and I don't regret it.
Currently run the 2 deltas and ctc i3 off that and my replicator pro clone from flashprint.

there are a number of other slicers out there - slic3r would be cura's main rival.
A good slicer runs the gamut between too many settings and not enough. For me, simplify3d hits the balance perfectly with more than enough settings to tinker with, but not so many that it's just bloody confusing (like retraction count :-) )

Quite a few threads around here listing alternative free slicers - it is worth trying them out.