@Kattous With sword, use your weapon action to help regen PP, each hit gives you 1 PP, a charge hit gives 10, but don't charge it up. Spam the single multi-hit, or get the skill that shortens the charge time when you combo a weapon action, it makes it instantly charged. So do 3 normal then 1 weapon action, or use your weapon action after every Photon Art, or whenever you remember. Basically, the weapon action regens PP better than normal attacks.
TMG, do perfect reloads, but don't hold it down unless you have time to. Tapping perfect reloads gives around +30pp. If you do a Photon Art, then a perfect reload, you will never run out of PP. Any attack after a perfect reload is a perfect attack. You can also dodge step into a perfect reload.
For Talis.....lol who uses Talis.
Jokes aside, it feels very underwhelming when compared to TMG and Sword. Even using it for the DoTs doesn't seem all that worth it. The damage of them is a lot less than a Sword/TMG photon art....so, might as well just use another one of those again.