Re: Weird Pre-delay strumming pluck?
I think it's just some type of delay, perhaps with a feedback and/or diffusion setting.
If you know you are going to use delay on something, you can freeze the effect to it's own track and then shift it backwards in time so that it comes before the cause. Also, you can reverse a track, then do reverb or delay, and then reverse it back.
It's probably the second technique.
Reversing stuff is a good way to get more varieties of effects.