For any ship that increases the size of waves, that is just for waves that are launched directly at that planet. Waves are the things that have the countdown timer, but they do NOT increase CPAs. CPAs are unaffected by any and all wave modifiers, because they are diffuse out in the galaxy, not launched against any given target planet.
So, to your question, if you have no hostile warp gates on any adjacent planets, the golem won't affect waves at all until it moves.
When it comes to the Sledgehammer, or any other AI type for that matter, their ships that are "free" and are roaming around under the Attack or Threat categories are not doing long-term targeting. Those ships are acting individually, and don't have awareness of what is on any planet other than their current one. So you can expect them to attack your golem planet sometimes if they are raiding near it constantly, but if the only raid point is on the other side of the galaxy they'll probably not make it there.
Best not to leave it completely undefended, but it doesn't draw ships like a magnet until they actually reach the planet, though.