Yes, the Eucalyptus does have an aroma. I think it smells very fragrant and I like it. Additionally, insects are repelled by it, so it helps cut down on those.

Tortoises can eat it accidentally without getting poisoned, but it can penetrate the gut if a sharp piece happens to get hung up somehow. I have had one Star Tortoise die from a perforated gut related to swallowing this mulch in 40 plus years. That seems like a pretty low probability of trouble to me. I also believe that wild tortoises eat loads of sticks, twigs, stones, and other items by accident and it doesn't seem to cause widespread death, so I just take my chances.

I have never tried to keep so-called "poisonous" plants out of my tortoises' enclosures, either. I figure if they eat the plants voluntarily, they aren't really bad for them. I have never had one die from ingesting plant leaves, flowers, fruits, etc.