Best Way To Share External Hard Drives on Network

OK, so let me explain my setup and situation.

In my basement I have my Retina iMac with three external TB LaCie Hard Drives. Two of them are older and one of them is a newer model.

When I am not in my basement at my desk, I have a MBP to use around the rest of the house. I want to be able to access my external drives from my MBP when I am not on the iMac. Currently, have clicked on the drives and set them to share. And if I go to finder and click on "Thomas's iMac" it lists all the drives connected to my iMac.

Now the problem is sometimes I will go to access one of those hard drive and it will say it can not be found and I have no clue why because its listed there. I forgot the exact message now, but its annoying. Normally if I reboot the MBP I can reconnect to the iMac and access the drives.

Is this the best setup for doing this or is there a better way to do this?

My main other problem is for some reason on newest LaCie Hard Drive will sometimes just disconnect from the iMac and I do not know why. I will have to reboot the iMac to get it to reconnect. I thought it was the drive itself and LaCie replace the entire unit, but I have the same issue. Any idea why this would happen?

Thanks!