Sudden change of leading in one style

But in my case Bold master is slightly larger than Light.

Well, looks like I celebrated too early. Now it’s broken in InDesign. Only this time it affect every weight:

http://cl.ly/N92U

The strange hinting is another issue for another time.

Can you send the current .glyphs file? I cannot reproduce this with the one you sent.

About the leading increasing or not: I prefer it to be the same across all members of a family. This has the advantage that a single bold word won’t shift a line. And IMO, what counts is not the height of the letters but the center line of the strokes. That’s why bolds appear smaller than lights.

InDesign uses the TypoAscender value to determine the first line offset. In the file you sent me, the value was too small: 136 (Light Master) and 166 (Bold Master). You probably meant to type 736 and 766.