1) You can become familiar with the parentheses. One might say, "all that white space" about Python, but that doesn't make Python any less powerful a language.
2) It does not look like what you're used to, but it certainly can work like you're used to since it is a multiparadigm language. Of course, programming Lisp like you program C or Python loses a lot of the power.
3) As a Lisp programmer, this is my biggest gripe.
4-5) True. If you aren't a contractor/freelancer that can choose your tools, Lisp is a hard sell.
6) Lisp is ancient. That said, the rest of the programming world has yet to catch up to the some of the concepts in Lisp like conditions or CLOS. Many of the "advances" in the new shiny languages have been in Lisp for decades.