Milan to Austria to Barcelona itinerary help for family trip

Going to Europe with family this summer and trying to keep the trip relaxed, not hectic 😭

Current plan:
Milan + 1 day trip to Lake Como
Then Austria (Hallstatt for 2 days)
Confused between Vienna vs Salzburg
After Austria we’ll go to Spain and fly back from Barcelona

A few things:
We need easy access to halal food
My father is a heart patient, so we want a comfortable route without too much rushing/travel exhaustion
We prefer scenic places, beautiful views, relaxing vibes, and must-see spots
Would you recommend Vienna or Salzburg for a family trip like this? And is there another place between Austria and Spain that’s really worth seeing without making the itinerary too hectic?

Also any halal food tips in Austria/Spain would help a lot 🙏