When are you supporting the song and when are you noodling?
If you're playing solo bits or what we used to call signature licks at the appropriate points in a song I'm sure you're worship leader is going to be happy with it.... at other points like a dynamically loud bridge where you might not want to play diamond chords or swells how do you assess whether you're moving from tasteful song supporting little single note riffs and into noodling.... For our purposes noodling means something like random pentatonic runs that although tied into the chord and harmonic structure of the song are things you might expect more in a blues song .
Doubling the vocal Melody may or may not be desirable that's up to your worship leader.... although it's safe in one sense it might interfere and unless you read sheet music it's another layer of memorization.