Yes, the father will protect them for a time, although I had 2 quite large batches and about half swam out of the shell they were in. I wasn't planning to breed, hence the shell being too small but it just happened. There were too many to count but there are loads of them so I assume they did okay.
Ensure they have plenty of cover, and food and they should be okay. The tank will get dirtier quicker as they get bigger, be prepared for more cleaning until you get them homed...
I haven't a clue how to get these fish to breed. I do have 2 caves for them but for some reason they preferred a crappy small shell I picked up on the beach that the dad could just about fit into. I removed it as I have too many, and they haven't bred since.