Metagross overall has fine moveset, it has 3 AOE spells + Gear Grind. Problem is his type combination, you will never find a place where both of its side will be used. You have to improve it by TM's.
You can improve steel side by adding one of cheap TM's, TM Earthquake (good for exp on rock pokes) or Sandstorm (good against ice pokes), if you got enough cash you can invest into Doom Desire or Metal Sound.
You can improve psychic side by adding one of cheap TM's Psycho Cut od Power Split.
If you ask for replacing any of psychic AOE for steel one, people who made it for steel part will be unhappy and vice versa.
Replacing Future Sight for Role Play may help a bit, and adding Metal Burst to its TM learn set will surely improve it's steel build, low cost, possibility.