Sounds like ya done right to start off with??, though ide be checkin coupla areas .
(1) Wiring, make sure nothing is earted to hull or body of boat anywhere.
(2) ide be removing all screws and small bolts or whatever in stainless and smearin that paste (yellowy,limey coloured stuff which sticks like shite to everything lol)cant remember the name of the stuff but is used for dissimillar metals and helps prevent electrolosis.
(3) check areas of paintwork make sure no paint is slightly lifting and trapping water beneath.
Apart from that ?? someone else may be able ta make some better comments??.
Cheers