Arrow keys are the worst placed buttons on your keyboard. You need to take your whole right hand of the home row. There is quite easy way of getting around it though. You can use Keyremap4macbook to remap left cmd + hjkl to arrows. Shortcuts that require cmd+hjkl can be pressed using right cmd (for example cmd+h to hide chrome) . Shortcuts that require arrows can be pressed using holding both left and right command.
Just open keyremap4macbook, go to tab vi mode and select arrow remapping shortcut of your choice.
Even in actual vim if I want to move one character while staying in insert mode it’s optimal way to do it.