I am reasonably confident I can replicate Rust's build system within the required 2 days for a limited number of objects, as long as you provide all the art assets for it. Make the object appear in front of the player, moving based on the view, snapping to a grid and to objects where it makes sense to be. Make them transparent green if it can be placed there, and transparent red if not (if it is colliding with something or floating).
I'm not sure what you mean by "clipped". Could you please clarify that? Also, do I need to handle the case where the object is placed on uneven terrain?
I have never used that particular inventory system, but the documentation for it seems pretty straight forward. At worst, I'll code you a new one to mimick Rust's. Do you want just the part about the inventory holding the required items, or the crafting part as well?
I look forward to hearing from you.