Yes, it will probably be too close to the frame.

No, you cannot add spacers because the axle of the crankset won't be long enough. This relatively narrow chainline is a standard for road bikes.

The chainline isn't defined by the chainrings but by the crankset, so, yes with the original crankset, it should work with these Litepro chainrings. Personally, I do not like Litepro cheap components, I would choose Stronglite but they are more expensive.

To mount two chanrings, you will also need longer chainring bolts since the one on the Birdy are mrant for a single chainring.