Advice on Kineticist: Single Gate Air or Dual Gate Air/Water?

Hey everyone,

As the title states, I'm currently creating a new character for our homebrew campaign. They will be a 7th level Nagaji Kineticist. I initially planned out their build with just the Air element in mind, as I do want the character to be sneaky and the invisibility impulse at 6th level did sound quite interesting for that in particular, however I am trying to see if I could possibly fit in Water as well for thematic/backstory reasons and to have some versatility in AoE impulse options perhaps, but I find it hard without sacrificing that which I had in mind in my original, single gate build.

Here's what I originally had in mind:

Level 1:

• Single Gate: Air
• Whisper on the Wind
• Aerial Boomerang
• Four Winds

Level 2:

• Kinetic Activation

Level 4:

• Safe Elements (For Desert Wind down the line)

Level 5:

• Expand the portal: Aura Junction
• Lightning Dash

Level 6:

• Cleas as Air

Level 8:

• Elemental Overlap: Desert Wind

Level 9:

• Expand the Portal: Resistance
• Cyclonic Ascent

Level 10:

• Aura Shaping

This will be combined with FA to grab either the Rogue dedication (Mobility feat & general skill feat improvements) or Monk dedication (Higher will save eventually, status bonus to move speed to not pick up the Air Aura possibly?).

Now, I'd love to know:

• Anything I missed on the single element build?
• How would you go about combining Air & Water while maintaining the initial character idea? I'd like to incorporate water at current level (7)
• How would Air/Water hold up against the damage output of mono Air?

Thank you for reading and I would love to hear your thoughts.