Try to ask one question per thread, please.
For the first question I know quite simple yet satisfactory solution. You limit the combo-box width to fit your layout. Upon opening of the combo box either make the options part wide enough to accommodate the items or if the content of a particular item exceeds the field's dimensions, you crop the content to fit the width and show it was cropped (e.g. three dots at the end of the string, or a small arrow right). On mouse hover you show a balloon with the full content, (hard) wrapping it if necessary, i.e. you set the width of the balloon to e.g. 60 characters and everything more than that ends up in the next line.
I don't know what is your locale and if you suffer from extremely long words (like German Fussbodenschleifmachinenverleih) but in most cases you should be ok.
One suggestion - if you're entering test data, try to use real-life-like data, use e.g. lipsum.com for paragraphs and mockaroo.com for fake names and addresses. Event the test data looks much better.