Would like to transfer an empty and un-lived in lot , from Psychosims' gorgeous Decorated Harbor neighborhood ; to my current Strangetown neighborhood.

Is it safe ?

So the plan would be to put the Harbor neighborhood into my sims 2 folder -- put the lot(s) into the catalog ; exit the game , and remove the hood. Then place the current Strangetown neighborhood into the S2 folder in my documents folder.
Then use the lots from the Harbor neighborhood in the Strangetown hood.

I'm playing both the decorated Harbor neighborhood and Strangetown ; just as completely separate games, neighborhoods, and stories.
Different populations and themes.

--- thanks in advance for any advice.

This isn't a problem. Uninhabited houses can go freely in and out of the lot bin, with no extra steps.

Not Maxis ones, they are also full of sim references which is why we have new guidelines on Maxis makeovers now. I would suggest cleaning any and all Maxis houses before using them. it's very easy now with Chris Hatch's add on to the Lot Compressor. http://modthesims.info/showthread.php?t=609188