jcmoussa,
p1p3 agree with your note.
p1p12 Glissa's Courier. You already have a green card, it might happen for you, and even if it doesn't it will do the same thing Training Drone does: sit in the sideboard.
p2p2 I think Darkslick Drake. 4 toughness + flight + self replacement makes him one of the better blue creatures. Maybe I undervalue the magnet?
p2p5 Again I agree with you, I would go towards replica, although blue tends to have a lot of 4 drops so I think the myr is reasonable too.
p2p9 Loxodon Wayfarer is a real card. I'd at least side it in against infect, although I guess Shape Anew is crazy tech if you just play 1 non bomb artifact.
p3p2 Here I'd definitely go with myr. You are not too likely to turn on the Warden, and 2/4 for 4 is underwhelming.
p3p4 Abuna Acolyte is a very underrated card imo. It really puts a hurting on infect.
p3p5 I haven't been keeping exact artifact count. I would take pinions unless you have 12+ playable artifacts already. If that's the case the Warden pick isn't as bad either.
p3p6 Same thing I said p3p5
p3p8 Unless you need this for constructed I'd take the Sunchaser if your metalcraft plan is legit.
p3p10 Loxodon Wayfarer is a real card.
After these comments I went back and counted your artifacts. You were at 8 before the warden, so I wouldn't be going for metalcrafty cards.