It generally depends on how much regular activities on your whatsapp account, if you have good conversation on your account and you have incoming messages as well including with outgoing messages activities then there are no or rare chances of blocking. If your account is newly created or having less regular activities on it, then we recommend to increase it's activities first.
No, you don't need to save contacts in your account to send whatsapp messages, you can send by simply importing contacts list in software through excel file, text file or manually copy paste method.
Transfer is possible, you have to install software on another pc, and you need to send us new request key, after then we will give you new license and it will replace older pc license automatically, so software will no longer remain active on previous pc.