Great, let me know how that goes. 
For future readers, here are some optimisation tips:
For Slices you grab all the info like:
{
blog {
body {
...on text_block {
non-repeat {
...non-repeatFields
}
}
...on image_gallery {
non-repeat {
...non-repeatFields
}
repeat {
...repeatFields
}
}
}
}
}
We explain that in more detail here:
For removing the whitespace you'll still need the new lines, so it will work like your example here:
{
blog{
body{
...ontext_block{
non-repeat{
...non-repeatFields
}
}
...onimage_gallery{
non-repeat{
...non-repeatFields
}
repeat{
...repeatFields
}
}
}
}
}
You can use this tool to do it for you: