Cocoa Bean-like behaviour on specific blocks

• For your first issue, you need to first make sure your block is directionally placeable, then just make a placement condition that checks the 'placed against' blockstate is your desired block. (If this doesn't work for some reason, you could also make a procedure that triggers when placed, checks if the block it's attatched to is correct depending on the direction, and breaks it otherwise, but that's not an ideal solution.)
• For your second problem, just make a neighbor block update procedure that checks if the block it's attatched to is still the correct block, based on the direction.

Not sure what's up with your code, it looks very broken. Do something like this for the 'when neighbor block changed. (This is for a six-directional block, you only really need the 4 cardinal directions.) You can do something very similar for checking if the block can be placed; just return true if the block at the correct position, (based on the direction it was placed), is your correct log block; or make a procedure that, when the block is placed, checks if the attatched block is the correct log type, and breaks the block otherwise.