Some questions

[Xenon]

1) Well depends on the main thing: what would your site be all about.
boards grow up very fast if it's a intresting main theme and your domain is good

2) depends on your host 25$ a month you should think of, but there are also cheaper solutions

3) applying hacks is very easy

4) look at vbulletin.com/forum everything you can see there is coded in

5) if you just want to apply hacks, you don't need to be a good programmer, if you want to write your own hacks you should be experienced in php coding. but it is very easy to learn if you want to and have a bit talent