I can still target on my main even after I die. So my alts still do what I want them to do. So you should be able to put in /castsequence [target=focus-target] Spells and have it work. But one part you mentioned is it is the same spells, just the targeting changes. So put in the targeting in first, spells last.

Code:
#showtooltip
/target [target=focus-target] [ ]  (first option should be the focus's mob, second one is blank which means that chars current target)
/castsequence reset=6/target/combat Spells