So... Whales are now considered fish instead of mammals now? It's crazy enough to be able to have 27 sharks in your backpack. Even with the lack of realism in RuneScape, 27 whales in your backpack just doesn't fit the fantasy. We already have enough fishes. Give an actual reason WHY you want something useless like whales to be added.
The Fishing Guild is better than Catherby because at Catherby, people are horribly mean there. At the fishing guild, you find that most people don't even talk.
I think that when we fight Slayer Monsters, we should get some slayer exp. Not as much as getting them from assignments, but an alternative. The exp you get from normally fighting a monster (4 exp for every damage you do. I.E. doing a 10 on someone gives you 40 exp) will be cut in half for slayer exp.