I prefer to use git-bash.exe instead of sh.exe.
start "" "%ProgramFiles%\Git\git-bash.exe" -c "tail -f /c/Windows/win.ini"
You can stop closing the window when call /usr/bin/bash --login -i
in the end;
start "" "%ProgramFiles%\Git\git-bash.exe" -c "echo 1 && echo 2 && /usr/bin/bash --login -i"
Note: I'm not sure this is a good way :)