#1
what are "perfect intervals" ie: perfect 3rd or 5ths? are they just normal 3rds and 5ths, or is there more to them?
#2
Seconds, Thirds, Sixths, and sevenths are major or minor. Fourths are perfect or augmented (sharpened) and Fifths are diminished (flat), perfect, or Augmented (sharp).

Sevenths can also be diminished, meaning that it is a whole step below a major seventh.