What you are proposing is, in essence, a scalping bot. I don't see any problem at all with scalping: indeed, it will help the scalper fill his pockets with money, while decreasing volatility and providing liquidity. However, to any would be donators: know that a lot of people are already operating bots like this, for free (or rather, they expect to earn money letting them trade).
Also, I find it ironic that OP proposes what is essentially speculation to end the problem of speculators.