Can I get rid of ether disease at any time? ... Do I even need to get rid of it?

[Typical_Name]

I got a parcel in the mail containing what is supposedly a potion to cure my ether disease. However, so far ether "disease" has only given me positive effects (well, my feet being hooves means I can't wear shoes, but it makes up for it with a +32 speed). Can I just save the potion for later in case I get negative effects, or will the disease eventually stop being curable through potions and/or kill me instantly?

Also, prior to my feet being transformed into hooves, I got a "mutation" in which my brain was "mechanized", is this related to the ether disease or are mutations entirely separate?

[Nov]

Separate. I also got the hooves "disease" and seriously considering keeping it too. IIRC antibody potions remove the last two diseases. So planning around that to decide whether to keep your hooves or not seems pretty safe.

[FDru]

Later on in the game, you can get such good equipment that those "positive" diseases won't be worth keeping. But for now you can save the potion. The disease will just keep adding mutations (some of which are only negative) but you can cure them when you feel like it.