i) how useful is it to just assign a genus? VERY USEFUL, it removes the damned thing from the project - everyone knows it's a MOTH!
ii) how useful is a tentative ID? VERY USEFUL, because between us we invoke the Likely Banner and so it removes the damned thing from the project - everyone knows it's a MOTH! Your added IDs are no worse than someone quite knowledgeable making the Observation and FAR better than the posters who made made most of these Observations anyway.
iii) does iSpot interlink with iRecord and, if so, should I exercise more caution? - er...NO. we prefer to go it alone, we have the very best observers, photographers and -ologists here - honest.