Using Forest Escape to get Zelda's Lullaby before beating the Deku Tree causes some odd side effects. Getting Zelda's Lullaby advances the Koriki Woods / Sacred Meadow Forest state, which allows you to get Saria's Song. But because the Forest is in a pre-Lullaby state, the two states conflict with one another, causing oddities. Saria will still stand in front of your house, but will have the same dialogue as she does in the Sacred Forest Meadow. Mido will no longer block the path to the Deku Tree allowing you to enter without a sword if you use a Deku Stick for the escape. And probably the most awkward of all, the Koriki boy that is trying to lift the rock will be making an "odd gesture" towards you...
When you return to the forest after obtaining Zelda's Lullaby, the angle to clip through the Kokiri guard is slightly altered. When you move down-left between the kokiri guy and the wall before the angle setup, only hold the control stick just past the ESS position so that Link moves very gently into the corner. If you move any faster and get bounced away from the kokiri guy at all, the escape will absolutely not work consistently.
As for the angle on the wall, it isn't strict at all. Just aim the sword's jewel in the middle of the entire green smudge on the wall, that's it.
