1) It's potentially the right attitude (4) S?D? The answer, apparently, is SIDE, but I don't understand why.
2) Kind old man returned theatre member's programme (5,5) ?R?E? P?P?R. I understand the definition (member's programme = ORDER PAPER) and I get that PA + PER = old man's returned theatre, but why does "kind" = ORDER?
3) Sub maybe busy, with rising sea level unknown (4,4) ?O?Y ?D?T. I get the definition of Sub = COPY EDIT, and I get TIDE Y reversed = Y EDIT, but why does "busy maybe" = COP?