User Manual BaoFeng GT-3WP IP67 Dual Band Two-Way Radio

It does not come with Programing cable

Yes, you can specifically program it to ONLY FRS if you wanted, but really the answer is that you can program it to whatever the radio and software will allow you to, and of course the FCC. Check the forums about transmit power to stay within FCC rules. RadioReference is a great resource. And of course google it. Chirp is a great programming software that is free. Good luck!

No. I would recommend you never submerse the radio. No radio is waterproof even the ones that say submersible. The first thing that will happen is the key pad will seize up. The waterproof rating is for using in rain or splash conditions only. If you want underwater comms talk to a dive specialist and get a wired intercom system. If you are going to use this radio in extremely wet conditions or salt water I would recommend you use a waterproof radio bag. I destroyed a $300.00 submersible HT radio by not using a bag and the radio was on my jet above water only getting splashed. BaoFeng GT3WP is a great radio.

You can use a Kenwood and a yanxuton 2 prong speaker mic but you cannot use dong to program. You use the screw to attach to radio on speaker/mic side then just plug in speaker/mic's.