Quick update on this guy. He has probably put on about 1-1.5in in the 2 months that I have had him, so roughly 8.5in now. Feeding him daily and doing weekly 50% water changes. He has been taking silversides regularly and ate some cod last night. He has stopped eating shrimp though.
He is finally getting comfortable in the past 2 weeks. He quickly went from not eating in front of me, to eating in front of me with lights off, to eating with lights on, and now not even waiting for me to step away from the tank. He also is starting to swim around the tank more and watch me more actively.
I will probably probably try pellets in the near future. Here is a short clip of him grabbing some food.