Is it possible to send one transaction to different addresses with different (or the same) amount of BTC?
Yes, go to the Send tab and fill the 'Pay to' field like this.
address1, amount1
address2, amount2
address3, amount3
Sending one transaction with multiple outputs is cheaper than a few separate transactions.
Yes.
Just put in the address followed by a comma followed by the amount and hit enter and do this until addresses are submitted.
If you have a spreadsheet you could also turn it into a csv and import that.
Should be in the form:
address1, amount
address2, amount2
Thank you very much guys!