I really do not see why he could not be crated while you are at work.  Many dog find it comforting to have a crate to go to when they want to feel safe.  As for crying to come out if it were me I would let him out when he cries.  I'd also make sure that his crate is associated with good things like special treats.  Many times if a dog is a puppy mill rescue they feel very secure in their crate so why take it away from him?  
 
Here is a great sticky with all kinds of info to read 
http://www.yorkietalk.com/forums/tra...nt-advice.html 
Let me add that Pebbles was crated as a puppy and for a while I took her crate away.  About 6 months ago I decided to purchase a new crate and she jumped right back into it.  When I saw how much she missed her crate I actually felt bad that I had taken it away.