While I am in no way a geologist(and know very little except the odd things my brain chooses to retain from news/tv shows), you would also want to indicate direction for the plates. Two plates moving apart is typically bad news for the local residency, especially if the area is close to the ocean and close to sea level(say for example... California) I would expect that to form a trough in water and sinkholes(or chasms) on land. Two plates that are "grating" against each other in opposite directions I would expect could form cliffs of some sort. And of course, a plate that buckles under another plate will create mountains..

If you are not opposed to adding to the map, you could use a bi-directional plate intersection to create a nice chain of archipelagos(bottom left looks like a great place to me to put a ton of islands, but of course this is your map....).

EDIT: oh yeah... I agree with Mateus, the land forms look really nice. Very well done.