After a good bit of trial and error, and asking questions... I have rewritten the override code and it works. (tested, slabs can now be used to make composters and barrels with this method.)
Fixed Stripped Bamboo Block Description.
Added in Bamboo Plank Recipe that uses Stripped Bamboo Blocks.
Removed double translation of "Bamboo Sign" in sign registration. (Caused the Bamboo Sign Errors.)
Added bamboo plank slabs to the group "wood_slabs" so that the barrel recipe works oob.
Michieal