Place softened cream cheese in large bowl. Add drained and flaked boneless salmon. Add onion and all seasonings. Add mayonnaise and horseradish sauce. Mix well with a large fork and keep mixing until well combined. Mix will be soft and ready to serve as a spread or sandwich filling. If a ball is desired, place in fridge for 2-4 hours and it will firm up a bit. Then scoop out mix onto plastic wrap and form a ball. Tighten the wrap and place in freezer for up to 1 hour to chill but not freeze. Right before serving, roll in finely chopped nuts.