my puppy did all these things too she'd snap sometimes when you stroke her but we say her name and tell her the off command, at first it didnt seem to work but we kept doing it and she still mouths but it doesnt hurt anymore, also she gets excited and tries to bite our feet and jumps up to bite us we still use the off command but if shes too excited we put her in her crate till she calms down and that usually works just percerveer and he will eventually stop.