You also have a space in between Cactus and .png in your Graphics/Icons and Graphics/Objects/Plants folder. You'll need to remove the space for those images to display properly.

You have some errors in your English.csv file that are preventing it from translating properly.
Here's a correction that will fix that:

Key,Translation,Version,Comment (context for translators)
Objects.Plants.Cactus,Cactus,
Objects.Plants.desc,Water x6 Plant Fibers x4,,
Obj.Materials.CactusMeat,Nopales,
Obj.Materials.CactusMeat.desc,Food Edible Tasteless,,
Obj.Meals.Nopales,Nopales,
Obj.Meals.Nopales.desc,Food Edible Tasteless,,