You can get/set only cvars and execute commands. You can't get console output after a command has been executed. If bot plugin does not have interface (i mean cvars to read them), you never detect what the value is.
By the way, "pb min_bots" - is a command.
And after all, you can work with cvars sequentally only: one by one. It a normal and sensible practice of programming. If you wanna minimize your code then store cvar names and commands in array and execute them in loop.