Well, first of all, welcome aboard, Cadeyrn. Always nice to see a new face.
Moving on to your questions, character sheets can be based on freestyle, or systems. Generally, the only time you need stats on a sheet is if you've applied for an RP which is using a particular system, though many people like to have such sheets standing by just in case. Most sheets, I think you'll find, are for Philsys
, which has become the house system around here, but there are also freestyle and D&D sheets scattered about.
As far as large islands off the map go, they're practically a certainty. There's plenty of empty map space, and even in those areas which are mapped out, I expect not every island is shown.