For SS1 you need the foloowing crew, BO,2 Torpman,planesman,sonarman, gunner is optional,I dont use it for weght reason's., Use bulkhead in armour instead of gunner.

Exp gain in a SS is gained by surviving ,and shooting torps, I use my SS1's mostly for defence ,because of limited air supply. 

Be advised that SN SS torpedoes don't have the same advantages over other nations that SN ship torpedoes do.  Whereas SN ship torpedoes are super-fast and quick-to-arm, relatively speaking, SN submarine torpedoes perform more or less like any other nation's.

... what?  they are fast, fastest sub torps.

torps give rubbish exp, its normal :(

and you need 1 bo, id say try get a rep+12 or elite and class as BO, 2 torpmen, 1 planesman, 1 sonarman, 3 engies and 1 rep for ss5