Welcome to the Source, flrn. Your english is just fine.
I know what you mean about Echoing Truth, though it is also useful against multiple hate cards, such as Meddling Mage. I am seeing more countertop now, however, so I have been seriously considering 4 Wipe Away in the SB, allowing me to switch out Remand for 3 Wipe Away, leaving me one to wish for.
The disadvantage of Wipe Away over ET or even Repeal is that it is slow. In the ANT matchup that you mention, I need to bounce Xantid Swarm on turn 2, not turn 3. Unlike most of my matchups, this one is not about going off as fast as you can, but preventing him going off. Wipe Away is too slow for this, and it is one of the reasons that I have not yet replaced the ET. Still, I am more likely to see countertop that ANT, and ANT is my better matchup any way.
I must admit that I have been avoiding Mystic Tutor; I never used it even when it was in my SB. It produces card disadvantage, gives your opponent information, and needs to be paired with a draw card during the combo.
By the way, Twincast is very rarely dead. If you do not expect counters it doubles your untap/draw/etc. If you do expect counters, it counters right back. That being said, there are often better cards in a given matchup, and so it often gets replaced in games 2 & 3 against aggro or even countertop.
I have been considering a new SB:
1 Brain Freeze
1 Meditate
1 Turnabout
1 Rebuild
4 Wipe Away (for countertop & other slow prison decks)
4 Disrupt (for combo and discard)
3 Repeal (for fast, broken permanents like Swarm & Lackey - though Echoing Truth might be better, as it is more flexible, albeit without a cantrip - ET is weaker against countertop, though)
Any thoughts?
-Silent Requiem
PS> I think you are on the wrong track with Whispers of the Muse. Peek was played over Opt for information. If you are not going for information, Whispers does a worse job that Opt of digging for answers or ensuring your land drops. And I rarely feel that I have 7 mana mid combo that could not be doing something better than drawing 2 cards. Wishing for a draw card could be more cost effective than that.

