Scrabble variation with diphthongs and consonant clusters

Hi! I'm thinking of adopting Scrabble (different board perhaps) to use a few tiles with multiple letters on them and some additional rules derived from tournaments (I was a low-level tournament player for a while).

1. Blanks make seven tile words easier and tournament players inevitably hold on to them to make seven tile words...so the bonus of 50 goes down by 15 points for each blank (minimum 20). Playing a seven-letter word which does not use all your tiles does not get the bonus.

2. A blank may represent any single letter, diphthong, or consonant cluster (all of the same type: e.g. Y, STR, or OU), even if it is not in the set. It scores N-1 where N is the number of letters in the cluster. This is backwards compatible with traditional Scrabble (N = 1). Y counts as a vowel.

3. One must know a word's definition to be able to play it. This must be supplied on a challenge. Most tournament players use words without knowing what they mean -- which will make the game educational too.

4. The board uses a normal Scrabble board and the tile back "empties out" after 100 tiles are drawn. You do not use all the tiles and have no idea which tiles will be drawn. In this case since there are never seven tiles left in the bag you can trade in at any time. Note that it is now longer possible to track for certainty. You can get 4 S's in a game or none.

5. The 200 tile set would be an expansion to be used on an ordinary board. It can also be used in its entirety on a Super Scrabble board. The game would come with the standard 100 tile set as well.

6. If a Super Scrabble board is used, the triple word scores close to each other on the new sections of the board compound to 4x (if the two separated by one square are used on the same turn) and 5x (if the two separated by three squares are used on the same turn). Trade-ins are forbidden with seven or fewer tiles remaining.

7. Under tournament rules a player has to play all his moves in 30 minutes on a chess clock. Tournaments normally use 25 but the multiple letter tiles make it harder.

8. There is no standard dictionary to cram for beforehand. A tournament will publicize which dictionary is used beforehand (or possibly announce it the day of the event).

Here is the 200 tile list.
Score Distribution Letter(s)
N-1 4 blank for N letters, all consonants or all vowels
1 16 a
13 1 ai
3 2 b
6 1 bl
13 1 br
3 2 c
4 2 ch
10 1 ck
13 1 cl
8 1 cr
6 1 ct
2 4 d
14 1 dr
1 21 e
5 2 ea
11 1 ee
4 2 f
2 3 g
14 1 gl
9 1 gr
4 2 h
1 16 i
5 2 ie
3 3 io
8 1 j
5 1 k
1 4 l
4 2 ll
4 2 ly
3 2 m
12 1 mp
1 6 n
7 1 nc
5 2 nd
2 4 ng
3 3 nt
1 14 o
16 1 oa
14 1 oi
10 1 oo
5 2 ou
3 2 p
4 2 ph
10 1 pl
6 1 pr
10 1 q
1 6 r
12 1 rc
13 1 rd
10 1 rm
9 1 rt
1 4 s
9 1 sc
7 1 sh
14 1 sm
8 1 sp
5 2 ss
2 4 st
1 8 t
5 2 th
3 2 tr
15 1 tt
1 8 u
4 2 v
4 2 w
8 1 x
4 2 y
10 1 z