Shyam has a truly shameless person. He's the type of person who will go to any lengths to get what he wants. As for Meher and Tarun, then no I don't think he ever did love them. From the flashbacks, I've gathered it was Suman and Devki who made all the sacrifices to make ends meet and to help run the family. Shyam did nothing. The only reason why he keeps coming to their home is the fact that Meher has money. If she hadn't then he wouldn't have looked twice at her way. Even now he's looking for ways to use the kids for his own advantage. So far we've seen him go to Devki and Kuber for money is because he knows Meher won't give it to him willingly.
He has no concept of shame or self-respect. If he had then he would have thought hard about his dirty actions a long time ago.