clothes split at the edges help please!

Not sure what you mean by "split edges" exactly but your uv_1 is bad:
- there should be an edge loop on your garment along the seam on your reference mesh for a clean transfer;
- DO NOT remove doubles before transferring the uvs.
All explained here from 00:00 to 3:30
To prevent the legs from poking out, remove one face loop. If instead of poking out you will see holes in CAS, select the top vertex loop and move it up a bit, you can also scale it down on each leg separately

1). Switch to Edit Mode ( TAB ) and in UV Editor enable sync;
2). Switch to polygon selection;
3). Press B, click and hold until you select the top face loop;
4). You can disable Limit selection to visible to see better;
5). Press Delete on your keyboard and choose Faces.
Save, import in s4s, try in the game.
If it won't give the desired result, try this:

1). Switch to vertex select;
2). Select one leg with B;
3). In 3D window press S to scale, G ( move ) followed by Z ( vertical axis ) to move it up ( if needed).