Soul Knife and Path of the Giant multi class

I am making a character called Odessa Stone, ( get internet point if can figure out where from).  Right now they are level 6 Giant Barb and level 3 Soul Knife Rogue.  At first I had a singular question but more look at character sheet I am wondering a lot more about the potential of this build.

So the first question about the Psychic Blades.  It states you can create one throw it and do 1d6+str/dex mod and with bonus action attack you can make second Psychic Blade that only does 1d4.  So I know Rogues always only have one main attack during their action, but would multiclassing into a class that gets extra attacks on their action allow more blades to be thrown or is it only still the two blades?

Second I'm looking at abilities and wondering if am reading right.  So say am in combat and decide to attack an enemy that a party member is also fighting.  So I creates Psychic Blade 1d6+2 (both str and dex are 15) Giant's Havoc: Crushing Throw +2 Sneak Attack 2d6 Strike of of Giants: Hill Strike 1d6.  So in total the attack would be 4d6+4 damage from a thrown attack?