Currently, no. Not even over feeding your pet will speed growth.
Honestly, no way.
The best way to speed up growth is to provide the organism with the proper food and growing conditions. It is not always healthy to speed up growth, although growth hormones can do this. Too rapid growth can have long term health effects on the organism.
There is no way to cheat on Runescape, may people have tried and lost runescape accounts over it.
No, you must pay to get a Runescape membership.
There is no way to manipulate your runescape skills.
There is no way to delete a Runescape Character, it always remains on their system.
There is no way to get money that fast in RuneScape.
No, The server that runescape is based on is way, way too advanced to be hacked into giving out free items.
There is no bestest Runescape building, they are all good in one way or another.
You can buy Runescape membership cards at target. That way you don't have to use a credit card online.
There is no Runescape 3, unless it's a virus, either way Jagex the creators of Runescape didn't create it that's for sure.
The best way to fish on runescape is to use a net or a fishing rod and bait in draynor. Then it is easy to bank your fish