UPDATED May 5:
I apologize to the forum for mixing two different problems. They are unrelated.
Problem #1: User error. I thought I was using a class 6 SD card but I was wrong. The yellow "!" indicates a pathologically slow card. Upgrading to a class 10 resolved this problem.
Problem #2: UNRESOLVED. Red battery indicator comes on prematurely. On a fresh charge, it'll turn red after recording for a couple of minutes. On a partially drained battery, it turns red immediately upon entering movie mode or pressing the record button. Turn the camera off and then right back on in "still" mode and it shows full charge and works fine ... until trying to shoot video. I have not precisely measured recording times but it'll record for at least 20 (maybe 30?) minutes while flashing red.