Who pays when a smart contract transaction occurs?

Question

We have a smart contract developed that we are planning to deploy on the ethereum blockchain.

Our question is

1) Who pays for each transaction made by the smart contract? 
2) Who gets the currency?
3) Who gets profited? 
4) Is there a way that developer(in this case is a group of us) always gets a part of eth after the transaction? 

Answer 1

1) Who pays for each transaction made by the smart contract?

When you deploy the contract, you pay for deployment. When people use your contract, they pay for using it.

2) Who gets the currency?

The miners. They mine and take the fees of the transactions, which include the "gas" cost of executing your contract.

3) Who gets profited?

Look at answer 2.

4) Is there a way that developer(in this case is a group of us) always gets a part of eth after the transaction?

No.

Answer 2

Who pays for each transaction made by the smart contract ?

Ans- For example, if we hold a smart contract which could be a program, if someone uses that program which consumes some gas from our account, the uses pays for the gas consumption to us with some eth. I,e User pays for the transaction made on our smart contract.

Who gets the currency ? Who gets profited ?

Ans - If you are the one who deployed the smart contract and created the block chain and if you had enough of ether for example 100, you assigned a miner to mine the block chain by setting the gaslimit. He is paid for the work based on the formula ( gas consumption * gas price). If you have any difference ether left then it will be yours.

Both the account user and miner may get profit or sometimes only ether.

Is there a way developer always gets a part of eth ?

Ans - If developer himself deploys the smart contract in his own account ( public network) and if any transactions made on it, I will get profited and that's the only way.