Mild climate is "welcoming and docile", not necessarily warm. I interpret it less violent weather than Earth (so no hurricanes, no tornadoes, nothing dangerous in terms of weather). Although I don't know if you can have both mild climate and extreme weather. I haven't seen it, but I don't know if the code will let it happen.
But yeah, it should be possible to get a random Terran planet with 50% hazard rating like Gilead now. Although given the 0.9.1a changes, it certainly seems less important.
Started a few spacer runs with the latest release, and finally got one to stick. You really can get away with not doing bounty missions at all and not even equipping weapons early game. By just doing exploration missions and not actually fighting anything early on, just running when caught, I've ended up at only suspicious with the pirates. Although I may have to change that stance, as Asharu just got a decivilization warning (and has a -9 stability penalty due to pirate raids).
Too bad there's not a diplomatic option to help stabilize a colony like we do for our own colonies, by maybe talking to the Admin on the planet and offering emergency supplies, credits, etc.
Apparently being only suspicious with Pirates has resulted in no pirate raids on my planets (using MN-1234567890 seed, vanilla RC7), which resulted in two terrain planets in Duzahk, plus a cryovolanic with abundent volatiles plus ores. Even with the spacer debt, I'm pulling in over 150,000 credits a month profit with a Size 5, 4 , and 3 colonies in Duzahk. Which is enough to pay off the single AI inspection, single Sindarin and single Persean raids, plus start some custom production runs (found an Astral blueprint so I guess carrier heavy fleet).