Speech to Text available via relay services. A little additional software would allow TTY text to be displayed. Full FCC volume range. Flashing lights all within acceptable flash frequencies. Not a problem on most phones today.
Headset being placed in jack cuts off the speaker - Standard industry practice.
Per Standards group ANSI C63 - Already being addressed by industry. Already common in many phones including world's smallest mass market cell phone. Subpart D - Compatibility Sec. How the requirements are met. Infrared port allows activation of all features remotely.