Nice buy! As others have said, you don’t have to do anything. The rifle is ready out of the box. Shoot it and see what you like and don’t. That said, I do a few things to mine:
First, I support your threading for a suppressor. To be threaded 5/8x24, the tikka lite barrel requires gunsmith to add a shoulder/collar, or thread it 9/16 and then add an adapter. Either works, just FYI. I sent my to Kampfeld Customs and he adds a shoulder and blends it. I also have mine chopped to 20” at the same time.
I also like the limbsaver recoil pad and vertical grip. With a Creedmoor you don’t need the better pad, but I’d probably add it anyway. It does add about 1/4” to your lop, I think. The grip is nice but not “game changing.”
I replace the bolt knob for mostly aesthetic reasons, but also to gain a bit more leverage when operating the bolt.
My rings are leupold backcountry one piece mounts or Hawkins precision one piece mounts. I also still have some Talleys that people say will break. All of those are somewhat limiting when it comes to scope mounting. Hasn’t been a problem for me, but you can always mount a picatinny rail and use rings of your choice if it’s a problem for you.
I also add a Henderson low profile 3” arca rail to mine, right in front of bottom metal. The factory accessory slot can be used for front screw, and you can either epoxy in a tnut or use a nylock nut for the back screw. Spacing will hit a gap in inlet of the stock with just enough space to work with if you hold your tongue right. The Henderson rail is really low profile too, so it doesn’t bother me like some others have.
On my elk rifle, I replaced the front swivel stud with a spartan javelin bipod adapter.
Enjoy the rifle!