Maybe it would be a good idea to have dedicated subforums here to sort the type of contributed resources, for example, subforums with the same name as the RPG Maker project folders (charasets, chipsets, facesets, etc.). It would be a bit easier to coordinate resources that way.
For pixelart graphics (charas, chipsets, even faceset and monsters), based on our experience, it’s important to define a common color palette first, so that artists can focus on creating resources. If not, it’s a good idea to have an artist dedicated to unify the style. Me and my brother can handle that, if you want.
For charsets I recommend to stick with RPG Maker 2000/2003 style. If you make them bigger, there is no space for poses (they were 24x32 pixels size, if I remember correctly). Also, I recommed to use 4 colors for part when possible (for example, 4 colors for the hair, 4 colors for skin, etc.).
For monsters, it’s a good idea to make them look like pixelart, so you should make them pixel art from scratch, or reduce the colors of a drawing and let it be fixed by the “unifier” artist. Also, all monsters should respect the original RPG Maker picture size. For example, if the original slime is 40x40 pixels, the EasyRPG slime should have the same size.
By the way, I have a Logic Pro 9 license, so I can handle the sound effects creation.
If you like the idea, please, open those subforums and move the posts inside each one, if appropriate. I can coordinate the graphic assets if you give me permission.