1. Yes, by mainly avoiding the Dinosaurs but also by finding guns and ammunition in the abandoned laboratories. You'll be able to collect seeds and plant them as part of the building mechanic. You could also cook meat that you collect and boil water to get rid of bacteria, similar to the game Raft.
2. The microphone just adds an extra touch to the immersion. It's up to the player if they want that enabled or not. I might come up with achievements in the future to award you for being detected and surviving certain dinosaurs.
3. Well building is more of just building and protecting you from the dinosaurs. Now while some dinosaurs have a chance to break your build for example a Spinosaurus or t-Rex you could upgrade your builds with better materials to make them tougher. I also added this mechanic because I knew if the only goal was to survive and find lore the game might become redundant or boring.