Very slight fert burn, no worries unless it gets significantly worse.
Try to keep the pH between 6.5-6.8. 7 is a hair high.
Yes, N def (SLIGHT) is good but not to the point where it shows as visible yellowing. I feed with bloom fert before cutting actually.
The plant should be uptaking nutes immediately now that the soil conditions are better.
And finally, give it a little while before taking cuttings- a week or so- but you're already in flower so shoot, it's 6 of one and half a dozen of the other. The benefit of waiting for the plant to be healthier may be outweighed by the problems that can arise from too much bud mass on a cut (possible place for rot to set in). Ehh do it now I guess. The plant looks healthy enough.