I want to say, "Are you sure you want to remove Alex?" Do I use
1: It's better to use
を I think.
Reason: If you say
アレックスは削除してもよろしいですか, people will think there are other things/persons that supposed to be removed sometime. In other words,
は is just not natural.
スタート is correct to use in this circumstance.
スタート is widely used especially in games and competitions.