Scobey:
For the Navy T-shirts, are you going to underbase the Columbia Blue or print flash print? Also, cotton or 50/50 garments?
For the Navy ink on Columbia T Shirt, - who's inks are you using btw? - I would start by adding 5% of a curable reducer and checking viscocity. If you feel the ink is still a bit thick, up your % to 10% total.
The inks will print well on cotton shirts, the print might be a little fuzzy from lack of fibre trap, but tis the nature of the ink.