At the current stage of the game's development, cheats are simply not needed in the game, it's like the fifth wheel in the cart. In fact, it is a kinetic novel with several choices and mini-games. It's not a sandbox where cheats may be needed. When cheats will be required - God only (and the developer at the same time) knows. I think that given the pace of development, not sooner than two years from now. Given my experience with other games, I only cheat for money, the other options can lead (not 100%, but a fairly high probability is available) either to the loss of some content, or to dead softlock (I so three times replayed Bright Past, just because of cheats leaded to softlock at some point).
For now, walkthrough mod or incest patch is more useful if you need incest (I play without it).
About game over - if memory serves me correctly, no, except that wrong actions or mistakes in minigames can cause you to not see a very significant part of the content. That's why I recommend the walkthrough mod.