u plug dongle into back of router
u configure dongle [if needed] within router web gui
router will allocate IP to any ethernet or wifi connection using router DHCP server & NAT
u plug any computer or laptop into the ethernet port of the router then in essence it should allocate an ip address [i.e 192.168.1.***]
like any other WAN connection whether cable or adsl, your router will secure and split the WAN connection using the ethernet ports on the back or wifi [NAT] and allocate LAn IP address using the DHCP server
it will be plug & play m8 with solwise gear and they have very good after sales
and yes u can use the ethernet and wifi connection at the same time
say for example your dongle IP address is 200.221.200.75 [ wan IP address ]
your Ethernet connection should allocate e.g 192.168.1.2 [local area network address]
your wifi connection should allocate e.g 192.168.1.3 [as above]
you can run a switch off the back off the router and the DHCP server could in essence allocate IP addresses to another 20 - 30 connections simultanously
it is the whole point of a router using NAT
ISP's offering multiple IP addresses is a thing of the past now - use to be an option as part of an ADSL package and I doubt many business packages offer it either