Sun Sep 25, 2022 6:08 pm
Generic answer to the question in title of this thread is: hell no!
One has to understand what bridge is: bridge (in context of question) is a switch-like entity. Most often it's used to join parts of network, "hidden" behind a port (e.g. ether2), with other parts of same network, "hidden" behind other ports (e.g. ether1 or wlan1). Traffic passes between bridge ports without any alternations (such as NAT) and without any filtering (e.g. firewall) ... in all directions.
Now, if you feel that network, "hidden" behind lte interface (that's internet), is the same network as the rest of your LAN ...
Said that ... if you know what you're doing and you're sure that's the right way, then ... why not, adding WAN interface to LAN bridge can be a legitimate thing to do.
Most of what you mention as requirements in your post can be achieved by some kind of NAT. What exactly needs to be done depends on actual network topology and requirements.
BTW, the question is not specific to LTE, it's general regarding any WAN interface ... as such, further discussion (if any) should go to another forum section (probably Beginner Basics).