There are plenty of valuables to be found! However, there aren't really many in the houses. If you want to swipe expensive jewelry, fine fabrics, trinkets that might look like they'd sell for a high price elsewhere, etc. then you will have to hit up the shops. ... But that's okay, everything is free anyway!

There's no way to exchange anything for credits in this system, but you could probably make off with a decent profit in later systems! It just depends on what later systems are like, and if you have something they would appreciate.