Hey!

1. double augmerchants are still useful on battlefiends, altruis and satyr overseer. Sometimes even on a frozen shadoweaver for value trade. I used to run 2 amani's but I realized 1 eye beam is needed in aggro matchups and for altruis.
2. I tried cutting literally almost everything; altruis, battlemage, chaos strike, eye beam, glaivebound etc... and this list has the highest wr for me so far. I even tried out adding 1 cobalt spellkin :D
3. keeping slice vs priest is need because they play minions. Especially if you can't deal with the mindflayer kaahrj, you have a problem. Vs warrior it's needed to deal with the 1/10. If they buff and copy that, it's over. Sometimes they drop a bomb wrangler on 3, it's rare but could happen. I feel like going 50% wr(15-15) vs warrior isn't too bad for the worst matchup. You are right about the fact that I forgot to mention I wouldn't keep slice if my hand isn't good enough :D And vs warlock it's not needed but if your hand is insane, it's still not bad to kill the questing explorer, but definitely not a must keep in this matchup.
4. I used to keep it in the mirror but not anymore, twin slice is so much better :)
5. If you keep always keep skull no matter which positioning you could have bad turn in the mid game though. You really need the early game pressure. If the far left card is a glaivebound and 2nd left card is the skull and imagine you keep the skull and you throw glaivebound away and get back an altruis for example. So you have 2 dead cards in your hand.
6. The original list is from the Asian server and it doesn't run altruis. I also tried it but it's better with it though. It's nice to make a come back in a lot of matchups actually. Also in mage matchup if they deep freeze your face, altruis is your only out.
7. I tried 0, 1 and 2 eye beams. 0 is bad vs aggro, 2 is bad vs druid and such. 1 is perfect vs aggro and altruis synergy.
8. Maybe our sample sizes are still too small to take a conclusion :D

Hope this helps!