Currently, many of the commands you reference can be executed by any role, including a "guest," believe it or not:
- tmsh show /sys version | grep Version
- tmsh save /sys config (without the file option though)
- tmsh modify /cli preference pager disabled
- tmsh show running-config...
- tmsh show /net route
The tmsh save /sys config file bigip.conf command (with the file option) can only be executed by an Administrator or Resource Administrator. Same for the netstat command as that requires Advanced shell access which is available only to Administrators and Resource Administrators.
As you noted, bigpipe is deprecated and replaced with other TMSH commands. Depending on what the customer is currently doing with bigpipe, they may require the Admin or Resource Admin role to do the same thing in tmsh.