man...what a hayseed. (okay...i just had to since you told me it was okay)...
1. you only need as much wire as necessary for any given speaker. always leave a little extra for "maintenance", but they don't all have to be the same length. some will argue this point...but i'll just laugh at them.
2. yep. never thought about that...that's a lot of plugs. be aware that not all binding posts are spaced the same. you may have to buy "individual" plugs instead of the kind connected together. no biggie...just something to consider.
3. all banana plugs that i'm aware of do NOT require solder. they are mostly clamped to the wire by friction of some sort. you either feed the wire through the plug, then screw on the top .. or you unscrew a plug, push the wire through, then screw the plug back.
4. yup!
[edit] there are no dumb questions...just people who are too dumb to ask them.

after all, that's what we're here for...so feel free to ask away!