There's no one set order, you should choose your spells based on the scenario you're in. Daemons? Light of the Heavens is great to stop their banner from activating. Vital unit's about to be charged? Mystic Shield. Etc.
Yeah, Chameleons can be extremely deadly in even a small number. They're ideal for almost any size army really.
So would this be better for 30 wounds Bastiladon Starmaster Chameleons 10 warriors Or should I keep the 12 warriors and the one salamander
I think it would depend on the kind of opponents you'll be up against. If your enemies often field high armour, take the Salamander. Light armour and the Chameleons may work as an Assassin unit while the Basi can deal with Rending.