I vote Yes to Ashnar's Mark and Sparkstrike. As for the third spell, I don't like the internal metamagic either, just because it's not the way the core rules generally handle spells with multi-level variants. In the interest of eschewing obfuscatory complexity, I'd suggest making three different spells, such as Lesser PE, PE, and Greater PE. Just because that's the standard way to achieve the same effect. Oh, and I want to think a little more about the appropriate level(s) for that one before voting on it.