Just before TB install you have 2 cre8 a database. Of course, TB itself can try to do this automatically, but it would be better if you create the database manually.
I showed needed commands. If you (can) use the phpmyadmin, there’s a tab in it, called SQL, you should open it and insert the text shown above in it. Don’t forget to select appropriate database, then replace database name, username and password with real data and run this sql command. After it completed with success you have to specify the database name, username and password in the installer.
Payment modules need a ‘reserved’ status. I don’t see this change happen in the core soon, because there are too many dependencies, but we will be releasing a payment module template with the functionality. Hopefully we can make as many payment gateways follow these recommendations as possible.
PHP 7.1 has been getting more stable though, but I would still advise to be careful.
I have recently switched to 7.1.10 in production, just to keep up with the latest developments and see how it goes, but I have been receiving lots of downtime messages. I’m still trying to figure out if it is related. In the error logs I can see that the PHP process just dies during the processing of a request, so I’m afraid that 7.1 is still not ready for production.