Confused with Xcode 4.5.x & old Developer folder?

[bunk3m]

Hi.

I'm confused and haven't found the answer to this yet.

I did an in-place upgrade from Snow Leopard to Mountain Lion. (Yes, I 
know a full and fresh install would have been better, but I don't have 
time to install all the various apps.)

As I use a number of MacPort apps I had already done a list of what I 
had installed before so I can easily do a clean install of MacPorts and 
rebuild the apps for ML.  I downloaded MacPorts for ML and deleted the 
old /opt folder.

Then I downloaded Xcode 4.5.x from the App Store.  Now Xcode is in the 
/Applications folder.  It used to be inside /Developer/Applications/ 
folder.

I see that the /Developer folder still exists.  And there is still 
another Xcode 3.2.6 installed.

What is the correct way to get rid of the old Xcode install?

Is it safe to delete the /Developer folder?

I also read on MacPorts installation that I'm supposed to be able to 
install the command line tools from within XCode.  Where is this?  I 
can't find it.

Sorry for the pebkac questions but I can't figure it out and appreciate 
some hand holding.

Thanks in advance.
B.

PS I'm on digest, so please cc me on any responses.