Remember that this is a splined crankarm & BB-spindle, not the typical square-taper set-up that's most common out there. Those actually require at a minimum 25 lb*ft torque on the crankarm-bolt, and best to get 30-33 lb*ft, depending upon the model.
Yes, on the FSA, the right-side crankarm is permanently attached to the BB-spindle. If you wiggle the right-side crankarm in non-rotating radial direction (in-plane with frame, up/down, forward/back without rotating), and there's no play, the BB & bearings is OK. This is most likely the case.
Then when you wiggle the left-side crankarm in any direction and there's play, it's due to the loose interface between the splines of the crankarm and BB-spindle. You'll want to take the crankarm off completely and clean off all the debri from between the splines on the spindle and crankarm. Look closely for metal shavings and burrs. Remove these with jeweler's file.
When you re-install, here's a trick I've found that ensures the crankarm slides all the way into the splines properly:
1. insert a dime or other thin metal-scrap into the gap between the pinch-bolt ears of the left crankarm
2. insert pinch-bolts into the threaded side of the pinch ears
3. once the bolts contact the time, tighten them 1/4 a turn, this expands the clamp of the crankarm slightly
4. slide crankarm over BB-spindle as far as you can push by hand
5. apply blue Loctite 242 on end-cap/crankarm bolt and torque to 5 in*lb (+0.5/-1.0).
6. unscrew pinch-bolts and remove dime
7. apply blue Loctite 242 on pinch-bolts and re-install from non-threaded side.
8. screw in pinch-bolts until all excess threads have been removed, then alternate back and forth between them about 1/4 turn at a time until you achieve 103-114 in*lb torque.