A single line in the spell section that read "A caster cannot for any reason cast more than one spell in a round" would kill a lot of potential broken combos.
Lets see if that line appears in the rules first.
There's no clear "one spell per turn" ruling, though the swift spell feature forbids the main action being used for spells or magic item activation.
IF the core rules package does not address the two spells issue, your concerns are valid.
Playtest document, How to Play p. 26:
"If you cast the spell as part of another action, that other action cannot involve casting a spell or activating a magic item"
I think that's pretty clear.