The sync issue, convert the mp2 audio to AC3 with BeSweet GUI or AC3 MAchine. Then use AC3 Delay corrector to change the time offset and reload and compile. Or you can use Maestro to author and simply drag the audio asset to the right to delay it further.
As for subtiles, in DVD2SVCD, tick the Subtiles Tab for Subs to be ON. When you ready to start encoding and click the GO button, in the first window that pops up, there is an option to "Add External Subtitle Streams" and procceed from there. If the Subs are not in the right format, then there are lots of Sub converters around, doom9 site has many.