ToME: the Tales of Maj'Eyal

Sometimes when I used "reload" on my archer, it actually reloads twice. Not sure if it takes additional turn, but my guess is that it does, which might be quite deadly.

ranks in the bow mastery talant allow you to reload more arrows in one turn, some egos do this too

This is correct. I reload 4 a turn, but sometimes it happens to be 8.

Reloads happen once per turn... if you're slower than 100% you get 2 reloads some times and if you're faster sometimes you get 0.

I've been getting this, occasionally enemies will act twice when I reload.

Are you playing a race with a speed penalty? I had a similar effect playing a ghoul archmage when Urkis got me on a one-shot. My build was flawed so my only possible strategy was to put up my shield, fire one spell then teleport away every time he approached me. Unfortunately one time when I was resting waiting for him, he came around the corner, saw me and fired in the double turn before I could do anything. I went from resting to the Eidolan plane with no warning. You may be seeing something similar here.

Hoss

Nope, it's been happening at base speed, and only when reloading.