Yeah i was afraid that Debilitating strikes wouldn't work since it specifies strikes. I don't see anything that can let Spell attacks trigger debilitating strike. Which is a big deal from what i can see since a lot of the Rogue abilities trigger off debilitating strike (master strike, bloody debilitations, etc).

I would think the magical trickster would count since it allows spell attacks to sneak but its ONLY specific to allowing that exact thing.

I agree Eldritch shot should give two but i have the feeling it will count as 1 for most DMs as i doubt they would want to let Magus get 2x SA on spellstrike. which is the equivalent.