Ah hell, who am I to opinionate but I'm going to.
I think this is on the right track but missing some elements. My bank is full, plain and simple, and I have more clues to do. What am I to do? If anything, have the clue shop purchase equippable clue scroll rewards based on clue tier for points that could then be used towards purchasing clues and/or clue boosters, clue scroll sack (after 100 Master clues), etc. Items should not be in there except items strictly pertaining to clues. For instance, unwanted clue rewards could be sold to the clue shop in exchange for points related to clues to work toward obtaining more clues without grinding but adding variety while allowing players to clean their bank even just a smidge.
Purchase
1 Easy clue = 25 points
1 Medium clue = 50 points
1 Hard clue = 75 points
1 Master clue = 100 points
1 Clue drop booster = ?? Points
Sell
1 Easy clue reward sells for 1-2 points
1 Medium clue reward sells for 2-4 points
1 Hard clue reward sells for 3-6 points
1 Master clue reward sells for 4-8 points
Perhaps donator tiers will increase point values (preferably not)
Clue shop can exchange for a Master clue.
I don't want to see Slayer items, barrows, vote, dailies, crystal keys, donation items, etc.
Meh, just my $0.02 at work. I think clue scroll incentive is welcoming nonetheless. Support in the meantime.