I had no plans to use the tapu koko and rather just leave them in the box..As Road mentioned, they'llconly penalize you if you use hacked Pokémon in battles. As long as you keep that Tapu Koko away from your Battle Boxes, they'll be fine.
If you're that afraid of linking the game to Global Link, however, you'll still get FC for participating in Global Missions. You just get half of the amount linked people get. The egg-hatching one going on right now is certain to meet its goal, so an unlinked game will still probably get 2,000 FC at the end of it, enough to get the five-star lottery you want with plenty of FC to spare.
She doesn't seem to let me join unless I link. I don't even see how there's an option to get the half.