The bass is awesome!
1. Many rhythm parts performed on bass use one note. Have you ever listened to a chord of very low-pitched notes? The sound is terrible! However, the bass guitar offers more than just very-low pitched notes, and chords can be used.
2. For me, the bass is easier to play because of the extra spacing between strings. However, if you plan to play complicated rhythms, just beware that the spacing between the frets is longer than guitar in most cases. There is an instrument called the Ashbory base that has an 18" fingerboard--it's quite tiny!
3. Both electric and acoustic basses sound good. It depends on the kind of music you wish to play. Electric basses will often be able to produce many different kinds of tones (especially with an active electronics system), while the acoustic bass can be somewhat more limited--though in themselves, they have gotten more complicated and often include equalizers.
4. You could go for Squire basses, but Rogue basses are good (and cheap!) as well. Or, you always have the option of going with a good (but overlooked) generic brand, such as Johnson. Such instruments are available at http://www.instrumentalley.com
I hope this helped to clear things up! Don't miss out on the bass guitar--it's one of the most overlooked positions in a band, but it's definitely one of the most important.