if you buy a pet slot and use a totem pet slot, those slots can never disappear if you abandon a pet?

No, the slots are permanent. :)

Nope, you get to keep the slots for forever - only thing is you will need a GA to re-adopt etc. if you have over 5 pets :)

& thank you for your help:) I keep forgetting the ga medal is needed..i need to remember that>.>