I'm encountering a slanted line above or below the note (not through the stem) and I can't figure out what it is (see measure 13 in the attached image)! A pianist friend said he would interpret it as a "scoop" or "smear." How should I braille it?
Also, is there guidance on a dotted/dashed slur, as seen in measure 12?
The slanted line under the note would be sung as a scoop or a slide into the note. For this, use the symbol for a rising straight line before a note, dots 126, 3, 14. This is taken from Table 16(E) Ornaments derived from Jazz Idioms. (Think of it as an upbow followed by a glissando!)
I usually braille the dotted slurs as dots 5, 123, 14. Dots 5, 123 are technically the "editorial prefix" from Table 21. Add the symbol to your SS list and call it the "Dotted-line slur."