A:AnswerThis is not a reasonable question to ask. The issue here is with how strong the cellular connection will be and that is determined by way more factors then can be assumed from your question.
If I were to give you some guidelines to your question then I would say with the internal antennas this unit has, you could possibly be about a mile to a mile and a half out at sea and have adequate signal strength IF the tower(s) are locates very close to the shore. Keep in mind this device is Cellular connected and requires linking back to the terrestrial cellular service back on land.
A:AnswerThe manufacturer's support page has this info:
-LTE/4G 1/2/3/4/5/7/12/29/30/66
-3G 2/4/5
https://www.netgear.com/home/products/mobile-broadband/mobilerouters/mr1100.aspx#tab-techspecs
A:AnswerI believe it is locked with at&t because they offer you the option to also get at&t service but Amazon sells unlocked nighthawk m1 mr1100 but for $100 more.
A:AnswerYou would have to sign up for a service that provides a static IP address from AT&T, but yes you can configure a static IP on both the WAN (LTE) side and LAN side.