This survey is based on a dump of spell usage done a server (I don't know which) on April 1, 98, one week after Renaissance went live. The dump is available here, raw except for having been split into schools and labelled by level. The repot shows how often spells are attempted, how often the casting succeeds, and other potentially useful data. The average spellpower is new in Renaissance and looks kind of glitchy, so I haven't really relied on it as a measure of spell effectiveness.

A 'cast' is defined as a successful cast (a cast which passed simple ability, eligibility, and targetting checks and thus used reagents). Touch attack spells use the physical attack code (note that the 'casts' field is always 0 since it doesn't run through that bit of code) and always use reagents, so for those spells a 'cast' is defined as an attempt.

Number of spells/skills

| Qor | Shal'ille | Faren | Kraanan | Riija | Jala | Weaponcraft
all levels | 23 | 25 | 19 | 25 | 19 | 5 | 13
level 1 | 3 | 2 | 2 | 2 | 5 | 1 | 2
level 2 | 3 | 6 | 4 | 4 | 4 | 1 | 3
level 3 | 4 | 4 | 4 | 7 | 4 | 1 | 3
level 4 | 7 | 6 | 3 | 6 | 2 | 1 | 3
level 5 | 5 | 5 | 4 | 5 | 3 | 1 | 1
level 6 | 1 | 2 | 2 | 1 | 1 | 0 | 0

Level of Usage (the popularity factor)

| Qor | Shal'ille | Faren | Kraanan | Riija | Jala
all levels | 24102 | 43478 | 29976 | 94551 | 15809 | 1457
level 1 | 5385 | 15462 | 9482 | 14226 | 8795 | 219
level 2 | 8063 | 3675 | 13640 | 31526 | 5999 | 515
level 3 | 8141 | 5362 | 1819 | 25134 | 437 | 624
level 4 | 1565 | 10434 | 1930 | 16608 | 572 | 97
level 5 | 948 | 8525 | 3060 | 6573 | 6 | 2
level 6 | 0 | 38 | 45 | 0 | 0 | 0

Average usage per spell (the 'dead weight' factor)

| Qor | Shal'ille | Faren | Kraanan | Riija | Jala
all levels | 1048 | 1739 | 1578 | 3782 | 832 | 291
level 1 | 1795 | 7731 | 4741 | 7113 | 1759 | 219
level 2 | 2688 | 610 | 3410 | 7882 | 1500 | 515
level 3 | 2035 | 1341 | 455 | 3591 | 109 | 624
level 4 | 224 | 1739 | 643 | 2768 | 286 | 97
level 5 | 190 | 1739 | 765 | 1315 | 2 | 2
level 6 | 0 | 19 | 23 | 0 | 0 | 0

Qor:

24102 casts total. 23 spells. 1048 casts per spell (this number is something of a 'coolness rating' for the school).

1: 5385 casts. 1795 per spell.

2: 8063 casts. 2688 per spell.

3: 8141 casts. 2035 per spell.

4: 1565 casts. 224 per spell.

5: 948 casts. 190 per spell.

Shal'ille:

43478 casts total.

1: 15462 casts. 7731 per spell.

2: 3675 casts. 610 per spell.

3: 5362 casts. 1341 per spell.

4: 10434 casts. 1739 per spell.

5: 8525 casts. 1705 per spell.

6: 38 casts. 19 per spell.

Faren:

29976 casts total.

1: 9482 casts. 4741 per spell.

2: 13640 casts. 3410 per spell.

3: 1819 casts. 455 per spell.

4: 1930 casts. 643 per spell.

5: 3060 casts. 765 per spell.

6: 45 casts. 23 per spell.

Kraanan:

94551 casts total.

1: 14226 casts. 7113 per spell.

2: 31526 casts. 7882 per spell.

3: 25134 casts. 3591 per spell.

4: 16608 casts. 2768 per spell.

5: 6573 casts. 1315 per spell.

6: 0 casts. 0 per spell.

Riija:

15809 casts total.

1: 8795 casts. 1759 per spell.

2: 5999 casts. 1500 per spell.

3: 437 casts. 109 per spell.

4: 572 casts. 286 per spell.

5: 6 casts. 2 per spell.

6: 0 casts. 0 per spell.

Jala:

1457 casts total.

1: 219 casts.

2: 515 casts.

3: 624 casts.

4: 97 casts.

5: 2 casts.

A partial transcription of the raw dump into a more readable format:

(I stopped when I realized that it was of limited use)

Qor:

level | name | casts | average spellpower | new
1 | darkness | 4066 | -5 |
1 | unholy weapon | 554 | 50 |
1 | unholy resolve | 765 | 44 |
2 | Kara'hol's curse | 1775 | 58 |
2 | detect good | 389 | 37 |
2 | acid touch | 5899 | N/A |
3 | enfeeble | 3400 | -28 |
3 | fade | 637 | 56 |
3 | hold | 4021 | 3 |
3 | animate | 83 | 54 |
4 | defile | 178 | 53 |
4 | curse weapon | 0 | 0 |
4 | poison fog | 95 | 49 | *
4 | swap | 195 | 52 |
4 | shadow rift | 0 | 0 | *
4 | Shal'illebane | 326 | 56 |
4 | vampiric touch | 771 | 0 |
5 | blind | 414 | 69 |
5 | death link | 88 | 87 |
5 | invisibility | 445 | 54 |
5 | nodeburst | 1 | 54 |
5 | blood inheritance | 0 | 0 | *
6 | gaze of the basilisk | 0 | 0 |