hey alexis,
sorry for the late response.
Here are your answers.
1.) As Cubasis is doing some signal processing dependently on your arrangement, there will be a tiny latency, like in any other App out in the market. It is optimized to be unnoticeable in most arrangements. We can’t give any numbers, since it differs depending on your IPad, the disk itself and your arrangement in the project. But there is nothing to worry about. Singing with a reverb insert is absolutely fine.
2.) Nope. Unfortunately you cannot set the loop record mode to be stacked. It is a feature request though.
3.) There’s two easy ways to get your audio into Cubasis. Use the WIFi Server provided by the App or ITunes File sharing.
4.) Yes it does. We only support Windows7 / 8 as well as Mac OS X 10.6 · 10.7 · 10.8
So unfortunately there is no official support for XP. There might be a chance it could work, but we never tested it.
Hope this helps for your decision.
kind regards
Ludwig