Sorry for the issues you've encountered with the SCLogin design. Most of the issues we should be able to help you fix pretty easily. I just looked at your site. Unfortunately, I can't give you answers to all of your questions because the module is in the sidebar now. If you'd prefer it in the horizontal layout, please enable that on some page of your site so we can test and provide the right CSS for your template.
Remember Me checkbox - Add the following to a CSS file on your site (either in the SCLogin theme or your template) and it will fix the alignment:
#sclogin-remember {
margin-top: -2px;
}
#2/#3 I can't help with since it's in a vertical alignment right now.
4 - The "forgot password" (and "forgot username") icons should be "into" the "password" (and "username") field. In this way if I enable only on of them, all the fields are still well aligned!
The standard way Joomla adds those icons is 'outside' of the buttons. However, the following style should move it over like you're looking for:
#form-sclogin-password {
width:87%;
}
That will make the whole password width the same width as the username/email input which is also set to 87% of the available width.
I hope that helps, but should you need anything else, just let us know!
Thanks,
Alex