You are correct that ANA's 77W's with the 2-4-3 configuration have fixed shell seats. If you are flying within the next month, then aircraft configurations are pretty much finalized barring unexpected operational changes. If you are flying further out, the 2-4-3 configuration may be a placeholder. As of now, ANA flies 77W's with the "old" 2-4-3 configuration on SFO-HND on all days except Saturday.

It has been a while since I last flew on these seats but, from memory, my experience was fine. Maybe lumbar support was not the greatest when reclined. Legroom might be a bit more cramped than the recliners but should be manageable with the 34-inch pitch.

Don't bank on a cheap upgrade. ANA does not offer cash upgrades the way United does (other than through bidding, but you must purchase your ticket through ANA for that), so you would need to pay the full fare difference which, as you note, can be quite expensive. If your flight is more than 48 hours out, you should be able to pick your seats on ANA's website.