1) We do regular dot releases for any bugs that are reported. We will be developing Powerstore 3 pretty soon, but the features have not been announce and are not yet publicly available.
2) This is supported in the current release
3) It is designed with our tools, and so can be updated with them. The difficulty of doing so depends on your familiarity with our tools, dreamweaver, and php as well as exactly what you would be updating.
4) There are lots of people on this forum that would help you here and/or be available as contractors, just ask when you need help and be specific with what you need and people will either offer to help for free or will give you a quote.
5) Not everything has in-line documentation, but some things do. The CSS should have some comments, since it was built with CSS Sculptor, but the html would have relatively few.