It's possible for Amba to survive the fight after she gets plowed by the Orc. It's just finnicky because she has 1 hp and you need to keep her from getting hit.
For the Bonelord section, asking the seemingly tangent questions will reveal the specializations of your minions. Send the Barbarian to the frontlines, the Logistics master to handle supplies. This is how you win the siege and get the Princess 2 scene (or the big-titty mage). Otherwise, you're stuck with the princess bj.
Okay, confirming that the only thing necessary for the Luci ending is for Love/V to get killed, which is the scenario that plays out when you skip the tower and go Bonelord route, then destroy the data.
This allows Luci to take the Captain's quarters in the shuttle, and the option to go see her will be available. Amba being alive doesn't matter, but you get no scenes with her if you don't save her from getting raped. You *do* get a funny comment before the final battle if you did Amba and also Luci (Asking if you at least showered first, which goes over poor Luci's head). Luci scene is a pretty vanilla spoon.
If you did the Luci scene, then Dorian will be hostile to you in the final battle. He doesn't have alot of hp and his accuracy sucks, but his pistol hits hard, so careful with that. He'll prioritize the orcs, but if all of them are dead the battle won't end and he'll start shooting at you.