Newbie question

Hi,

I just started using Blender, just as you're talking about this group
going away!

I'm a scientific illustrator, and I've worked for 20 years in
Illustrator. 

Many of my illustrations involve irregularly shaped cells that are
having interactions with each other or with molecular structures.

I've spent a happy few days going through the Blender basics in the
manual, but I still have some questions.

I want to be able to pull in some of my line drawings from
Illustrator. and then turn the cells three-dimensional with
smoothly-curving surfaces. I've figured out the import part, and I've
then also figured out that I can convert the shapes to mesh and
extrude from there.

What I get is a shape that's like my old drawing but thicker and with
vertical walls.

How can I make the whole shape poof up like a balloon and with no side
edges at all. Is there a way to extrude to a curved surface?

As a bonus question, where is Z-trans? I'd like to do shapes inside
translucent shapes. I figured out Ray trans, but I see mentioned here
and there that z-trans is better.

Thanks for your help!

Don't go away!

Best, Valerie