I got all achievements two days ago in a 9 hour run, I'm not sure what you did wrong.
I also got the Boom Shrimp after defeating the crab, I'm presuming this is a simple .lua script with a mistake in it.
Also I'm not sure what went wrong with the explorer bug, because again, I got all achievements. Not sure what you might've skipped, do you have all pets as well? What about the easter egg, maybe you went in there, got the achievement, died, then it missed the area?
I found two crashes myself, which is;
Opening the minimap with q button while changing map.
Then cooking something, pressing q to open recipes list and then pressing escape to close the window, all within a second.
Both were able to replicate.