i have lightroom 5 .....if i download TIFF files from lightroom onto an external hard drive, and download those files on to another computer ....can those files be adjusted/ worked on in that computers Lightroom. My issues is I'm doing some high end printing and want the printer to be able to adjust what i've developed in my lightroom in case what i'm seeing on my computer secreen doesn't quite match up with the actual Print quality.
I don't see a connection between the two issues.
Yes, you can copy photos to another computer and work on them in Ligthroom.
If your prints don't match what you see on the screen, you don't "work on them in Lightroom", you have to properly calibrate your monitor.
The best way is to export from lightroom to give that to printer.
If printer wants to make some adjustments he can do that in photoshop on his/her machine.