Have had this dog for 2 1/2 years, but can no longer keep. Have found a good home but are wondering what do you think about visiting a pet after giving it away? Is it good for the pet or is it bad? What do you think?

Honestly I don't think it is a good idea to visit it, especially not at first. When a dog gets a new owner, it needs time to bond with them, and if you keep visiting it, it may still think you're it's owner and it could be upsetting for the dog. If the dog has any separation anxiety after you give it away, you visiting it will make it worse and will make it harder for the dog to accept its new owner.
If the owner lets you visit and the dog does okay then you can try, but if it seems like it bothers the dog at all afterward, don't do it.

It's more if you think you can handle it. The dog I think should be ok because it sees people all the time.

If the new owner lets you then why not. The dog would be happy to see you again.

if you truly love your dog then yes. give your dog frequent visits and try to be friends with the new owners.