Great Vowel Shift and spellings

The current English spelling has not changed since Middle ages; however, the pronunciation has shifted since then, thanks to great vowel shift (GVS). And this process is not uniform (cf. Neogrammarian hypothesis vs lexical diffusion). I am not going to delve into this, as I focus more on exceptions to several heuristics taught in phonics classes.

1. -east breast
2. -ear  bear, tear, wear, swear (cf. fear, sear, shear, hear, rear, beard )
3.  -ea- great, break, steak (cf. freak, creak, bread)
      breath, death, breast, deaf, heavy, heaven, threaten, tread
4. before /k/: book, brook, rook, cook, crook, hook, look, took, shook, nook; exception spook (from Dutch). Boogie is short, boogieman variable
5. before apical stops: blood, flood (note the preceding clustered liquids)
   soot, foot (lower); food (higher); good (fronted and often lowered)
   mood, brood

   before apical fric: goose, tooth, sooth (exception paroxytonic bosom)
  moon, spoon, soon, noon
   done, none, spl cases

labil env:
 glove (shwa); stove (oh)
  dove, shove, plum, trouble, couple, double (schwa_
  light apical fricatives: dozen, cousin, mother, other, brother (schwa or further lowered)

2. -ou-: you, youth, uncouth, soup, Cowper, etc (cf. sour, cow)
     route (check AmE and BrE)


Will be added as I refresh my memory!