So i was thinking if i send a bitcoin transaction without the miner fee or a very low fee what will happen ? would i get the coins back eventually ? or they will just stuck there forever ! and if that happened how to do that double spend ?
I don't think you can send bitcoins with zero miners fees. If you send with a few lower than what is recommended, it may not confirm or it will take a long time for confirmations.
The point of the miner's fees is to make it worth the miner's time to confirm the transactions. We need the miners so that the system won't collapse. We can't have Bitcoin without miners.