Smoothing landscape textures

[Razorwing]

I like to switch out landscape textures through the menu you get by pressing the "I" key while in landscape editing mode. It's a handy feature, but I think it's what's responsible for a lot of blockiness in the landscape's texture around Soluthis. I'm guessing but it seems like replacing textures in this manner makes the landscape forget the transition between textures. So far I'm smoothing them by hand, but I thought I'd ask if there is any way to smooth the textures automatically?

Also while I'm at it, this might be a silly question, but is there a way of seeing in the world window the grass that will be generated on a landscape texture? I've always tried to steer clear of landscape textures with grass on them just because I tend to make mistakes since I can't see the grass.