It's major reach indeed.
I don't know...? I think it would be good for Silas to be with his dad and his big sister, because that's his normal. Having a probably confused and scared 6-year-old changing his routines more than he needs to doesn't seem like such a great idea. Also, if he's staying at a hotel with Heidi's parents (which, I don't know if that's the case, but they don't live in Texas) that's not a very stable situation. He needs his bedroom, a place to do his homework. Now, if Shane asked Heidi's parents to keep Silas for a little bit so he could be his head on the right place and get back on his feet, that's different. I don't doubt that Shane is having a really hard time, but I can't see how Heidi's parents could be doing any better.
There was no name change. The "friend" that killed Heidi and took Margo told someone that she had just had a baby, a girl named Luna Mae. We know Luna Mae doesn't exist, she's not real. There's only Margo.