counter surfs - lock her up behind a see-through gate in a well traveled part of the house during the parts of the day she’s the most trouble.
paces - this may be a mental thing as a result of the meds and/or condition.
begs for and steals food - is she fed from the kitchen around meals or dinner table? stop if so.
chews up the kid’s toys - buy her chew toys and scold heavily / lock up any time she chews up something that isn’t hers. my dog eats anything made out of synthetic fiber and is proving a major pain to train otherwise.
eats out of the trash - get a flip-top heavy / decorative trashcan, like this: “http://homeimprovementstip.com/wooden-trash-bin-for-kitchen.html".
jumps on guests - this one is the trickiest, but also seems the least of your issues.
This sounds like normal dog behavior to me.
We used a shock collar on our dog...but he’s a 90 lb Pit Bull
The squirt bottle thing worked better then the shock collar. All we had to do is pick up the bottle and his bahavior changed. Until he realized he could drink the water shot at him....
Put the dog up during meals, or at least give it a raw hide or something to chew. They can smell the goodies, so of course they want some too.
Put the trash where the dog can’t get into it....it’s a dog...they like to put their noses in all the wrong places.