Trouble with encryption is most likely to be from one of your plugins. If you're not able to get a fix for that, and alternative to try is using Enigma Virtual Box to pack everything into a single .exe. As with everything, it's never going to be fully secure, but I think it helps to the download look a little neater too.
You could probably get away with just using show pictures for the items unless you need extra functionality. Sumrndmdde's HUD Maker is easily one of the most powerful HUD tools since you can use javascript evals. If you wanted a different kind of system there's Atelier RGSS's Variable HUD which shows the total number. It's nice since if the player walks under the image, it'll turn semi-transparent, but I'm not convinced that it'd fit from what I've seen in your game.
I hope more people stumble upon this demo! It'll definitely be a hit with people in need of a bit more action in their lives. For me there were definitely some hard times since I'm sloppy. I could have done with some extra lives or maybe a one hit shield XD You probably need to find a way to ensure that always dash is automatically turned on since the game isn't very playable without it, but otherwise I hope that you're really proud of everything you managed to get done with such a short deadline, and I'm sure you'll go on to make something great! Good luck with development!