No. There is a creative tab called "Pre Opened Cases" However, to open the crates in survival, you need to put a crate in the bottom middle slot of a crafting table, and put the corresponding key on top.
If you need help with this, I will take screenshots
EDIT: Regular crates are found in the decorations tab, however crates that are already crafted with keys are found in the pre opened cases tab
Maybe. I have stopped working on the mod and don't actually have the MCreator workspace for it anymore. However, if you can code or if anyone wants to they could start working on it again. Sorry to disappoint you
However, there is one mod that I am currently working on. Its called the Siege Mod.
Concept based on games like Clash of Clans and Clash Royale.
Again, sorry to disappoint. This mod was the the first mod I made and I am proud of it.
After the Siege mod is officially released, I am planning on making a much better remake of this mod, with many guns and a variety of Cases.
Until that happens, sorry to disappoint. AND now I feel like an idiot because I said sorry to disappoint more times then my current balance on steam