an X4 is basically a combination of the X2 and X3. It's fine to use all of those 3 on a BA. If a brand new X4 fails, you can get a replacement from the same tuner you buy it from, so no biggie there.
1, you didn't include the photo... (instructions here)
2, there's no intercooler pipe that runs to the block or any pipes that come from the intercooler piping that goes to the block, so we've got no idea what you're referring to.