Glad you're enjoying the game, and thanks for your support!
The percent chance for rare capturables to show up in the game is something that is pretty hard to express as a single number. For some of them, it's something like "when rand(0, 200) < 10, looped three times" to see if there's a chance of putting the random item on up to three planets. And it varies by item, some (like AI Troop Accelerators) are very rare, most are not all that rare but may be in inconvenient spots in some maps.
For Golems, there are always a few on the map if you're playing on 40 or 80 or so -- I think the minimum is around 3. You can see how many Broken Golems are out there waiting to be fixed in the Mission Objectives list on the right side of the screen. One important thing to keep in mind is that the capturables/superweapons/golems are the most incomplete thing about the expansion so far; I think that around maybe 6-9 have been implemented so far, out of the 25-30 that are on the list for completion. As those additional capturables arrive in the expansion, they will automatically be inserted into existing savegames if you load the existing savegame into the new versions with those capturables; so as the expansion is finished, you'll definitely be seeing
vastly more capturables scattered around the galaxy.
