If you have a razer naga, a g15 or whatever you can create macros and scripts.

If you decide you want a spam button with a naga this is what you do. Create a macro, uncheck the insert delay button and then just hit all the buttons you want to be activates. The naga hits them all at the same time but for whatever reason, Swtor is actually prioritizing the keystrokes so the first key at the top of the macro actually hits first.

This was talked about openly in beta and people were asking about it frequently due to the official razer/bioware partnership for the swtor launch and the lack of an actual macro system.