CSS Layout design

I have been exploring best way to bring customizable CSS layout design that would fit wider variety of audience. CSS with countable properties is kind of huge thing for me. It carries so much important aspects ie layout and aesthetics (themes) of front end and also we can play with it with the change in line of code. As always, making it simple is tough.

1) How do I design a layout templates so that it caters wider variety of audience

2) How do I change certain curvatures like rounded corner

3) Fluid vs Fixed layout and option to have both

4) How about doing it with Javascript like jLayout or JQuery Masonry

JQuery is doing fairly great job of DOM scripting and UI is not so fair as it touches here and there and providing something not very much useful to enable templates but doing nice job of theming.

Blueprint has been one of my favorite CSS framework for sometimes but 960.gs is also similar but doing similar task of blueprint. Almost these two guys hates fluid based layout with good reasons.

I really agree that CSS is territory of designers but having that abstracted out would really makes life simple. I wanted to do templating based on CSS and html alone.

I am going to use 960.gs for fixed width and fuild grid based on 960.gs for liquid design. Using little server side program and dynamic configuration, trying to bring custom design (Layout and theming)