1) All AKL rooms have balconies (even the pool and "parking lot" view rooms).
2) I wouldn't worry too much about construction just now. There are 3 construction projects scheduled over the next few years.
The first one is the building of a new animal barn at the end of Kudo trail. It's being built outside the lodge, and reports are that it CAN be noisy...but only for those rooms at the end of Kudo Trail. It also wouldn't surprise me (after seeing recent pics of the buid out) if they were finished long before your trip. In any event, they can't start building the new building until this project is complete.
The 2nd is the conversion of the 5th and 6th floor rooms into DVC accomodations. That construction is entirely (or nearly so, except for balcony conversion) interior. That could generate some noise between 9 AM and 5 PM, if you're staying on the fourth floor in an area being converted. Almost 1/2 that project (IE: all of Zebra Trail) is scheduled to be complete BEFORE your trip (as those rooms are actually "opening" on Sept 1st). Which leaves only the 5th floor rooms on Kudo trail, the 6th floor rooms around the lobby, and the Ostrich and Zebra trail rooms. Because of this, and because of the time you're going, I would put in a request to stay on Zebra trail, on the 2nd or 3rd floor (just in case). Heck, anywhere on the 2nd and 3rd floor and you're likely not to hear any of the interior construction.
The third is the building of the new Kidani Village building which will be DVC only. That building has not yet even started construction. When it does, it will be on the sunset savannah side of the lodge (completely OPPOSITE side of the resort from Zebra trail) and MOST of it is about 1/4 mile from the lodge itself, across the savannah. I doubt you'll hear anything from the site IF they've even begun construction. If they have, you might see some vertical construction out past the boundaries of the sunset savannah if you're looking out that way.
To summarize all that: Put in a request for a 2nd or 3rd floor room on Zebra trail and you'll likely not even notice there is construction going on. Obviously, things could change, but given the time table we have, and the reports that have come in....I don't think they will.
3) I"m an AKL/AKV enthusiast so, IMHO, it's certainly worth the extra $$, even IF there was construction going on. But I'm admittedly biased.

Remember, with CBR, you're trading some amenities off with a deluxe, but you're also trading off "convenience". AKL has better transportation (because it's one bus stop, and they don't share), and while huge, it doesn't feel as "spread out" as CBR. JMHO.