Answer 1

RUT104 is quite an old device. It's support ended on 2015.11.20 https://teltonika.lt/product/rut104/ 

So it is really hard to tell. There is a thread about this on OpenWRT: https://openwrt.org/toh/wiligear/wbd-111

You can try to install it, but some features of the device might not work.