Beguiling Voice, the Maestro bloodline lv1 ability reads:
rules:
Beguiling Voice (Ex): At 1st level, you can use the sound of your voice to lull a target creature into taking no action. This ability acts as the daze spell, except it is language-dependent, has a duration of 1 round, and affects a living creature whose Hit Dice do not exceed your sorcerer level. You can use this ability a number of times per day equal to 3 + your Charisma modifier.
Am I reading it right that it is a Daze, that the target's max HDs as follows:
Sorc level 1: 1HD
Sorc level 2: 2HD
...
Sorc level 20: 20HD.
Or am I missing something? Can I somehow affect up to HD4 before level 4 as normal Daze?
You are correct.
There are one or two magic items that increase your sorcerer level for your bloodline powers but i dont remember their names.