when completley replacing the motor in my 2010 Chevy Ipmala; do I need to move the transmission or hoses that are connected to the transmission?

Yes. It will require several transmission realignments to install a new engine in ANY vehicle. Best of luck. The Impala can be especially difficult.

well, those are coolant lines...you really don't wan't to mess with those...perhaps replace them~ I might inspect the transmission mounts and see if they are sound yet~ seems like it would go easy with two mechanics to help ya~

I would not take simplification of the job, by trying to leave everything alone...this may backfire, because there is a lot of Dirt under there and trying to put it all back together CLEAN would take a lot of brake cleaner~ definitely disassemble what you need to, but not having done the job myself...there needs to be a measure of clearance..you're going to have to remove the hood, for example...wish I could speak with authority on your subject..."what can I get away with"? and sadly have NO advise~

Thank you for the help! I'm asking because my car is currently at the dealership because they are replacing the engine; BUT they called and said I now have transmission fluid leaking from my engine when it was not leaking before....but they claimed they did not have to touch my transmission at all to remove my engine. This seemed fishy to me.

perhaps they damaged the lines...let them replace them...you are at their mercy...sadly~ of course it's fishy...that's how this business rolls~

not from the engine....transmission fluid DOES NOT leak from the Engine...but can leak from the lines goin' to the radiator...often this flexible connection made of rubber treats the driveway to a shower of transmission fluid~

if they insist the front seal is leaking...have them show you that ...then Replace the leaking seal...they are like 15 bucks...but HOURS to get to~