Fusible link or not?

There is a relay that powers the distribution block. It is not hot all the time. The power comes from the leads from what was the ballast resistor. So it will be active during cranking and also during run but not during keyed off. So that should not drain the battery, Correct? I may need another block and relays for those that need to be powered during accessory only, Lights, etc.
Correct.
That relay may need to be a heavy duty unit. More precisely one that can carry current for multiple circuits.