Again, logging in once a week/month would only happen if you were at all flagged by the system, it's not expected of everyone.
The first part of the formula is designed to find who should be flagged, but it doesn't cause anything to immediately take effect. So a level 1 character would only be flagged if they were created and then instantly set aside.
If you at least play for a little while you'll be absolutely fine, it just encourages people to make use of the characters they have created so you're safe, even if that's just idling in Atlas Park or RPing somewhere. Same applies to level 50s who were farmed up, but the system is more forgiving of that.
Then the safety buffer gives people who have been flagged the opportunity to log in, and that would be enough to remove the flag.
If you're flagged and you dont log on at all, that's when your name may be up for grabs, but you're safe if nobody else attempts to use it.
it's a fairly forgiving three step process in my opinion.