Does being saved by grace give a Christian permission to live loosely?
No. Grace is not license; salvation by grace does not permit loose or permissive living. Paul teaches that those who live should no longer live unto themselves but unto Him who died for them and rose again, so believers are to live for Christ.
Les teaches that grace is not license. Just because believers are saved by grace and kept by grace, that does not give them permissiveness or license for loose living. Paul constantly puts this in front of us: it is all based on Christ's death, shed blood, burial, resurrection, and power, not on keeping the Law or the commandments. If we have entered into eternal life, we should live for the One who died for us and rose again. Therefore there is no room for permissive living or a loose Christian walk; we are to live for Him because He died for us.
And that he died for all, that they which live should not henceforth live unto themselves, but unto him which died for them, and rose again.