Hi Moledady. My name is StraightTalk Stephanie and I will be addressing your question. Please be informed that BYOP program only support GSM technology. Please check the below answers to your oultined questions:
1.) You can use WiFi if your phone is capable of doing that free of charge.
2.) We do not sell wireless modems. The phone can be tethered to your computer to transfer data from the phone to computer or computer to phone but cannot be used as a modem to obtain an internet connection, that violates the terms of service”.
3.) BYOP supports T-Mobile and At&T services only. If you have coverage in your area with this networks, your phone will work.
4) We do not offer discounts for additional lines.
5) Only AT&T, T-Mobile compatible GSM phone or an unlocked domestic GSM phone will work with the BYOP (Bring Your Own Phone) Program. To view program, please visit www.straighttalkSIM.com