Does anyone know where we can find the weapon and biotic attack sounds etc??
Weapons... try searching for the .afc files.
example... "SFXGUI_W_A_Vindicator.pcc" there you will find a series of sound files, that when compiled together will make the given sound of the rifle/weapon. Or the file named "SFXWeapon_AssaultRifle_Vindicator.pcc"
But if you're looking for heavy weapons sound effects like the mini nuke explosion.. it will be located in a seperate file for example titled "Wwise_Weapons_Heavy_MiniNuke.afc"
For biotic sounds they maybe located as files like... "SFXPowerMP_Slam.pcc" so on and so forth. Along with those biotic sounds you may also encounter a number of other power's sound effects like the "SFXPower_Overload.pcc"
And the if you noticed there is a "SFXPowerMP.." and a "SFXPower..." One designed for mulitplayer pressumably and the other for single player.
I hope this helps you!