Rime spell says that the target becomes entangled for "a number of rounds equal to the original level of the spell" which in the case of Ray of Frost would be 0 rounds I believe... unless there is some hidden rule about "minimum 1 rounds" that I missed.
Conceptually, rather than focussing on inflicting as many debilitating effects as possible, you might be better served by focusing on inflicting (a few of) the most debilitating effects possible.
If you can hit someone with a really brutal condition like nauseated, who cares if they're shaken? "Creatures with the nauseated condition experience stomach distress. Nauseated creatures are unable to attack, cast spells, concentrate on spells, or do anything else requiring attention. The only action such a character can take is a single move actions per turn."
An alchemist with the stink bomb discovery can be AoE nauseating groups of enemies left and right, starting at around level 3 or 4 for example.
For the magus, frostbite (magical lineage) + rime spell + enforcer seems like it offers a lot of bang for your buck, at least against enemies vulnerable to nonlethal damage, although it eats up two feats and a trait. A fatigued, entangled and shaken enemy has some pretty hefty minuses! Still, a nauseated enemy is much more debilitated than a fatigued, entangled and shaken one.
Bombs are alchemist level + int per day. +2 for the extra bombs feat, which as a PFS character I believe you get instead of brew potion. Gnome favored class bonus gets you even more bombs. And you don't need to nauseate every round, because it lasts several rounds, and by then you'll probably have killed most of the enemies anyway. Once per combat is plenty!
If you want at-will debuffs, what about a witch? A human witch could pick up evil eye, misfortune and cackle at first level (take extra hex as both your feats), and be at will debuffing all over the place. Go take a look at the witch hexes!
Frostbite you can use for 1 attack per caster level. You don't get Spell Combat, but if you do a lot of moving around or just want to max your resource management, it's a great spell. Let's take a level 5 Magus as example...
Round 1: Cast shocking grasp, move and deliver. Successful hit yields, say 1d6+5 damage for the scimitar lovers, plus 5d6 electricity damage.
Round 2: Cast Frostbite(with Rime), get free touch attack and deliver through Spell Strike. 1d6+5 weapon, 1d6+5 nonlethal cold damage (triggering Fatigue, Shaken from Enforcer, and Entangle). Take next attack for another 1d6+5 + 1d6+5. Total 4d6+20.
Round 3 would only get 1 attack with Frostbite, unless you decide to cast a spell after your 1st attack (such as another SG or FB, triggering Spell Combat again).
You can easily do a lot of damage and screw people up. Who needs "save or suck" abilities (which almost all BBEG will make) when all you need to do is touch the bad guy and you give him 3 nasty effects.
An alchemist with fast bombs can freeze (stagger) someone and knock them prone in the same round: pretty nasty having to use a move action to stand up when you only get a move OR standard action in the same round.