Final Cut Express-only problems! (RT,rendering etc)

Hey everyone,

I finally got my macbook pro 13" after years.. love it.
I'll use it mainly for video editing and i have over 30 hours to edit. I did some stuff in iMovie and its pretty simple. Then i got Final Cut Express and it seems to give me only problems.
So far i have only brought projects from iMovie (although i can't export "raw footage, but only "projects"..?). As soon as i brought them to express i got no audio and a lot of beeping. Then windows came up saying i may have to lower my RT (or something) and i may have to render etc. I did some research and i made an attempt to render....something. I'm still not sure what part i rendered, but part of it started to work. I know that express doesnt bring audio from imovie etc. and that audio has to be in AIFF.
Another window pop-up was about playback drop-off, and how maybe, my computer isnt fast enough..?!?! (its a bran spankin new MBP 13" 2,4 ghz.....and im using an external hard disk)
So here are my questions. Please help me with your most simplified phrases.. i'm a quick learner, but im completely new to mac's and comupter "language"..

- Are these problems mainly because i'm importing from iMovie? whereas if i imported from my videocamera directly to express,id have no problems??
- If i import from my camera to express (no iMovie) will i still have to render EVERYTHING?
- Most of the music that i will add to my projects will come from itunes..does this mean i will have to render or convert ALL the songs that i will use to AIFF??
- Is my macbook pro really to slow? how to solve the "RT" or "playback dropoff"?
- Is there any way to just start editing without having to convert,change,render,drop,lower,higher fricken every single clip??

imovie was simple beacause i could get to work right away..

To sum it all up, if anyone can give me a brief layout to how to start using express, that would be great..
THANKS SO MUCH!