Taranis will not give you signal strength warnings without your setting it up. It's up to you to decide what levels you consider as low and critical. Same for battery level warnings.
Taranis will however make you a cup of tea if you want... ie you can make it do just about anything you want. The penalty for this versatility is the level of complexity. That is compounded if you cannot get a USB connection and program it on the PC. Although comprehensive, the documentation in OpenTx University in my experience was not always enough to explain in full.
If you are prepared to buckle down and do a lot of reading you will be rewarded. After more than a year I still need to refer to documentation quite often, and there is often more than one way to do anything.
After a while doing things like setting warning levels looks easy. I would not want to take your hand and walk you through it. Going to OpenTx documentation + the manual should explain better than I can.Be persistent.
Are you sure you cannot get a USB connection. There are a lot of "help me" articles out there as the bootstrap setup is rather confusing, and does give people headaches.