Your many troubleshooting attempts show that you can start your Mac in SMC bypass mode, thus you’re left wit two basic possibilities:
* Bad battery
* Bad SMC or related circuitry.
Disconnect battery and see how it goes. If everything gets back to normal without it just replace battery, regardless of the apparently “good” condition.
If problems are still there with battery disconnected you have a board issue requiring component level troubleshooting and repair.