I didn't check for shutdown, only reboot, because the pi is remote ATM and no easy way to wake it up back.
I renamed the pi user, everything seems OK but this. Here're info I gathered after reading a similar post about add new user+delete pi user:
me@mypi:~ $ groups
me adm dialout cdrom sudo audio video plugdev games users input netdev gpio i2c spi
me@mypi:~ $ id
uid=1000(me) gid=1000(me) groupes=1000(me),4(adm),20(dialout),24(cdrom),27(sudo),29(audio),44(video),
46(plugdev),60(games),100(users),105(input),109(netdev),997(gpio),998(i2c),999(spi)
me@mypi:~ $ sudo cat /etc/sudoers.d/010_me
me ALL=(ALL) PASSWD: ALL
Many thaks for help