If I use Magical Lineage (Spark) with Silent Spell, what kind of action does it play as?
What class are you?
Are you a sorceror? then it's a full-round.
As a wizard, if you prepare it as a silent spark, then it's still a standard.
May I ask why you are trying to do this?
Wizard.
I want to be able to set things on fire without being detected. :)
Then you prepare it at its normal casting time.
And sounds cool!
Also, I may combine it with pyrotechnics, but that goes without saying.