I don't think much changes at 50nl, speaking for pokerstars anyway.. you can play like a rock and 8-table on autopilot and be profitable up until about 400nl (although it's definitely not the best way to progress your game).

I 100% agree with whoever said not to loosen up too much, or at least do it very gradually. It's just a matter of determining your hand's EV in specific circumstances...which you should always be doing of course, but when you're playing more hands it's especially important because bad decisions are compounded. Remember, 90% of losing players are just bad LAGs.

Don't raise J9s UTG because it seems like the "LAGgy" thing to do, raise J9s UTG because there is good reason for you to believe you have the best of it in doing so. Experience is a huge factor in making these decisions.

my 2cents