IC2 in current stage miss few "generic" recipes.
Coding every possible plant clump recipe combination to allow different plants stack is not way (anyway this wont work with buildcraft autobench), may be recipe to convert any plant into plant chunk?
Shapeless 1:1 any plant into plunt chunk, and recipe to use plant chunks to craft plant clumps.
This will make automated biofuel factory a bit easie.
Sand+Gravel+Water into clay using both cells\blocks (it crafted from UUM)\bukets.
Clay block to clay
Clay to clay Block
Glowstone to glowdust
Glowdust to Glowstone
Charcoal into normal coal (may be redstone + charcoal == coal or something like this, currently charcoal only 4k energy and nothing more)