Hi

Good suggestion from Kiwi

look at the tutorial movies that come with the program too - they will help with the basics


short answers:
question 1 - use 'set line width' box [control bar] together with 'scale line widths' button [selection tool mode infobar]
question 2 - searching the forum is usually a good idea, here is one related thread: http://www.talkgraphics.com/showthread.php?t=28289
question 3 - use layers - sometimes outline view will help if all the objects are on one layer, but use of layers is very important to efficient use of the program IMO.

Hope this helps