If I booked a cruise through a travel Agent, Would I have to put down the same deposit that I would have to put down if I booked it through the cruise company?

Yes.

Yes you would.

In most cases yes. However; some Travel Agents may have group space on the same cruise you are looking at. Sometimes they may require a small deposit, then a second deposit by a certain date. The total of the two deposits would then be equal to what the cruise lines original deposit request was. It is always best to give the full deposit though. On group space, if the full deposit isn't made the cruise line could recall that space if needed. Although it is a rariety that they would do that.