Splits happen for time to time, usually it is due to mechanical damage (bumping into it or such) I cant see the brown spot you are talking about , just keep an eye on it. If it gets worse then you have a problem. Keep the leaves dry ( don't mist them or let rain sit on them as foliar diseases spread with water drops, not saying you have one just a general comment) Your plant has been disturbed: moving to your house then being potted, so that might have something to do with the form not being as tight as it was when you recieved it. How long have you had it? More than the 2 weeks you mentioned on the repotting? So far it looks good. Just keep a close eye on it for awhile.

Sansevieria die most often due to wet plus cold conditions. Damp roots in winter rot fast. A Sansevieria will take moist soil in warmer temperatures (as in above 70), but it is best to allow them to dry out before rewatering. Test the soil for dampness prior to watering. Good luck and don't hesitate to ask questions.

The rocks on top will make it much harder for pups to emerge, but looks great! I love rocks & wouldn't remove all of them, just some, which would also allow much more oxygen to get into the soil, moisture to evaporate more quickly.