Sound Deadening/Proofing for a couple of rooms

A soundproofing needs to be comprehensive and you need to consider all possible "flanking" paths where sound vibrations can travel between rooms to be isolated. Rod Gervais' book on Home Recoding Studio building is an excellent resource.

Main points are that the most efficient wall/floor/ceiling construction for sound isolation is three layers. No more, no less: Mass - Air - Mass (M-A-M). The outer mass layers are usually drywall, two or three sheets thick laminated together and the center air space filled with fluffy insulation. One of the Mass layers should be mechanically isolated from the other mass layer with either separate framing or resilient channel (RC).

Broadband absorption is for treating room acoustics and will do little to nothing for for sound isolation from room to room.

Your PDFs show good ideas but you need a comprehensive plan. If you spend time and money but fail in any critical step, much of your work and expense can be negated so start with Rod's book.

Cheers,
Rock

IIRC, Rod recommends fluffy. I think this is because with a large enough "AIR" space, fluffy is cheaper and just as effective. I'm pretty sure you can use rigid FG as it will not conduct or "short circuit" mechanical vibrations. You might consider posting on "Gearslutz"  www.gearslutz.com/board/studio-building-acoustics/ and see what they say there, maybe Rod will answer you directly? Having said all that, the rigid again is more expensive so make sure you wont need it for treatment once the isolation or sound proofing phase is complete.