i just wanna share gamay ako experience from shipping dogs...
@ #1 - when i canvassed for a dog (initially in manila) pirme nako iapil sa purchase cost sa shipping para wala hassle... usually dugangan ra ng seller iya price to cover for the gas & freight costs... then sila na bahala ana... dawat na lang ka diri sa cebu... just dont forget to get the flight details of the dog...
@ #2 - pay thru bank accounts... in that way, you got to know their real name

it would be very important to get from reputable sellers... you can always check their previous posts and, if there are available, reputation ratings... in DTO, PPF, etc you can more or less know who are the well-known sellers.. get from them, youre at least assured they wont 1-2-3 you
@ #3 - usually the papers go with the shipment... depends on your sabot
@ #4 - definitely mag una imu bayad... its scary but thats the way it is... if you find a seller thats amenable to ship first before any payment (whether downpayment or full) you have to be worry about it... i was scammed previously when a supposedly seller from pampanga agreed that i pay partial first then she'll ship the unit dayun... sus, after i paid, nahanaw na pod siya... atay lolz...
hope i helped in answering your questions.... good luck