BIP9: What happens if I make a segwit transaction after lock in but before activation? Will it be treated a anyone-can-spend or do the nodes enforce the new rules? 

Along the same lines, what exactly happens when we say a soft fork is activated?


Are the enforced at the time SF becomes activated?
Or they are always enforced from the moment you download the client, but we consider it safe to use after activation?
The new rules are come into effect only when the softfork activates.

I am not completely sure, but I think in the case of segwit transactions these would be treated as non-standard nodes and thus not accept it in their mempool. If a miner does have it in their mempool, they will not mine it into a block.

Hopefully, everyone that receives it would immediately drop it, but I think that third parties could pick the input up with an ANYBODY_CAN_SPEND transaction. They'd need to deposit the transaction directly to a miner that mines this type of non-standard transactions though for it to be mined.