My question is, in her text she said she will have 1/2 of the rent the 1st, then "should" have the second half with the late fee two weeks later, so she gets she'll be paying extra.I don't want to be soft and encourage this type of habit to form, but I don't want to be a jerk and evict her right off the bat either, especially if she warned me a week in advance.Would you serve a 5 day notice on the 6th when the grace period ends?

And I could ignore any calls from mommy.I actually only had to kick out one undergrad for relentless parties, regardless of warnings.  

I would give them a verbal warning to the same affect even if you don't have it in your lease.

He was trying to warn potential buyers that unpermitted work had been done in the house.

That's probably why all the landlording books give warnings about letting people slide on their rent. 

She has been keeping the apartment clean and there have been no more problems with others living there, so apparently my verbal warnings, about non-tenants who were seen living there, were sufficient for her to change that and comply with the lease.

If they did, they'd get a stern warning as I don't have the patience for txt spk.

If a tenant chooses not to use the vent, that's on them.So, provide a quieter fan if you just don't want to deal with it (which would be my choice) or give a written warning to the tenants that disabling the fan is a violation of their lease agreement (I'm sure you have a clause about damaging the property or making alterations without permission), and they need to knock it off - and that any damage resulting from them disabling or not using the fan is their responsibility.And of course, you can always not renew their lease.

Mold Warning StatementMold may grow and exist in any structure where there is, or has ever been, a presence of moisture and a food source for the mold to grow.

Be warned; there are companies on the internet who readily provide this certification by someone in the medical field which the applicant must pay a fee.