Feedback is always appreciated so thank you for taking the time to right up your thoughts.
1. I hope you aren't resetting your run over locked treasures! Just to be perfectly clear tarot card chests are entirely randomized loot. You will never miss a unique magic ring or story item from them. They are simply chances to get some more expensive items, like bullets, for free.
2. In regards to the Firespitter, and all enemies in general really, escaping from battle is pretty hit or miss at the moment. Some enemies are properly programmed to stand still and allow you to walk through them and some are not. This is simply because enemy behaviors are not fully fleshed out and it is kind of a luck of the draw as to if I copy and pasted a default enemy with those settings properly set up or not. This is also why many enemies reuse tarot cards or show the incorrect death sprite. This will absolutely be fixed by the time of the full release, but has not been a high priority yet unfortunately.
3. In regards to Mac I myself do all my play testing and development on a mac. I can't say I typically experience any performance errors when running the game however. The only times I can recall the entire game becoming laggy was when I was trying to capture footage and running OBS or other such applications. Wish I could offer more help than that!
Thank you for playing and I hope you enjoy your time with Red!