I see you already added the following to your custom template file:
.sclogin-modal-links a {
margin-right: 17px;
color: #fff !important;
}
The margin isn't working because you didn't add !important. You can fix it that way, or alter the class selector to be even more specific, like::
.sourcecoast.sclogin-modal-links a {
margin-right: 17px;
color: #fff;
}
I think that should work.
As for the "/", that's defined in our en_gb.mod_sclogin.ini file. You can make that any other character, or blank, by changing that file or using the Joomla language override system.
I hope that helps,
Alex