Soup Sandwich
Kill everyone in a specific way (doesn't all have to be in the same run)
1) Ram Parvati and Rose
Follow the "Point Man" opportunity and complete Parvati's training drill with Rose watching. Make sure you turn off the ram safety before the exercise starts (run through the opportunity once so you know where everything is and what you're doing). If you do well, Rose will join in the debriefing to commend you, and both targets will be in the path of the ram.
If tampering with the safety or hitting the ram button makes someone Suspicious, just run out and around the barn. Once you break line of sight for a while they will lose interest and forget about what you did.
2) Make Berg blow himself up
Follow the "Tongue Tied" opportunity. At the start, while you're in the supply shed for the basement key, take a wrench and open up the big red gas canister. Make sure you hide any loose bodies or guns so the AI doesn't get distracted. Complete the opportunity, and once Berg finds out you've tampered with his interrogation he'll (eventually) make his way back to the shed and ignite the gas with his bunsen burner.
3) Drown Graves
Follow the "Audition" opportunity and talk to Graves at the slurry pit. She will dismiss her bodyguards and lean over the edge of the pit with a huge neon "PUSH ME" sign on her back.