How can i fix formatting issues with the shopping cart and shipping pages?

When a customer is ready to check out they're presented with the your shopping cart page.

Two things:

I would like to hide the have a user account? fields completely and just have checkout now button.

My other concern is formatting this page with general css to correct padding issues and fix the table layout. The same could be said about the shipping address information, where input fields are butting up against the description of that input field.

I'm not looking to get crazy with custom design, the current things displayed are fine, just want them cleanly presented and spaced comfortably.

I have screenshots specifically showing the issues, i just dont see how to append them.

any thoughts?