Thank you for contacting JustAnswer.com with your question. I will provide legal information related to your question.

In KY unless your support order states that the parent must pay after high school, then the obligation to pay support ends when the child turns 18 or graduates high school.

Yes if the order is silent then it ends by law at 18, that is the default. To get support during college the order has to specifically state that or you can go back now and ask for a modification to get a court to order support while she is a full time college student.

Yes if you want to seek a modification.

If he did not avail himself of his right to visitation that is not something that the court will address because he basically gave up his right, but the order did not force him to exercise his right to the visits. It would be important to the judge if he were now trying to force the kids to visit or now claiming you kept the children from him and he should not have to pay support. As far as the porn, if one of the children is still a minor you could report this to the court to get a contempt order for him being in contempt, but since the minors are not visiting already there not must else in the way of punishment that the judge will seek.