I'd modify that slightly - retraction 1-2mm I currently use 1.8 for pla - cuts down on stringing and blobbing, which cuts down on the print head catching bits of plastic and buggering up the print.
And first layer speed 10% - the slower you put the first layer down, the more likely it is to give you a good print and stick to the build surface.
Yeah it can make a the print a lot longer - but you get a lot less failures during printing, so gain in time in the long run.

What surface are you printing on ?
ie: kapton, pei or painters tape.
Pva gluestick over tape.
etc

It does make a difference :-)