.. alternatively, you can increase the auto-complete delay - this gives the chance to type a few characters before the auto-complete list pops up.

I was unaware of this issue. The file setting "auto-complete":true causes auto-complete to be triggered automatically when typing. Changing this to false would then require Ctrl-Space (or Tab) to display/use the completions. This setting can be made syntax specific.

In the meantime, I'm quite proud of my own JS completions file https://github.com/agibsonsw/AndySublime