Home Use, IP passthough to TPLink router

After google and searching this site I am reaching out for some help. I am not as well versed as most of you on the forum so forgive the questions if not very technical oriented.

We live in rural area and one of our cellular routers, Pepwave max Transit cat18, the wifi did not reach enough of our devices so I disabled the AP and added a TPLink AX6000 to handle wireless, enabled the WAN port to LAN. I have my PC connected to the Max Transit LAN. Our other router is the Balance 20 cat 18 (AP disabled) with the Pepwave AP1 providing wireless. We have excellent WAN quality and low ping on both routers, I am trying my best to optimize both routers to best settings for our home, but my technical knowledge is being stretched.

1: can I bridge the Max Transit using IP passthrough and use the TPLink as the ethernet and wireless router?
2: will I still be able to connect to the Max Transit after setting IP passthrough?
3: do I need a static IP from AT&T in order to do this?
4: would this solve Strict NAT issues with gaming platforms?

any configuration tips in any regard are appreciated