I agree with slayer rewards not being as satisfying, but trust me, these are not the rewards you want. There is a reason nobody buys them from the blood shop either.
Keys and clues - easily obtainable content, does't need to be even more.
Nobody buys gem, herb, bar boxes and if they do - they're wasting their time and money.
Why do you need a herb sack if you have a RoW?
Bonecrusher would be nice, but it's honestly not as great as people think. 200m prayer is fairly easily obtainable and the passive xp training would be cool, but wouldn't really matter that much.
Not against these ideas, but not really supporting them either, would rather see something else being added to the slayer shop.