Iruka is only for your linuep, but shields like ao's or mabui's or konan's hit more than one lineup. Guy's leaching effect too works for the whole field, but the 30% atk boost is only for one lineup. There are some misunderstanding and mistranslations in general.

If there's no translation mistakes then 'team' refers to the 4 ninjas you put on the field, 'lineup' refers to the 4 ninjas + summon/clones/pets, 'Field' refers to the three lineups you can have in gnw, ranked or tis.

about your assumption, yes, if says 7+ targets then is a field effect.