Those topics have been covered in depth dozens, if not hundreds of times on HN.

http://lmgtfy.com/?q=site%3Anews.ycombinator.com+choose+part...

http://lmgtfy.com/?q=site%3Anews.ycombinator.com+startup+loc...

http://lmgtfy.com/?q=site%3Anews.ycombinator.com+incorporati...

http://lmgtfy.com/?q=site%3Anews.ycombinator.com+startup+ide...

http://lmgtfy.com/?q=site%3Anews.ycombinator.com+market+fit

http://lmgtfy.com/?q=site%3Anews.ycombinator.com+merchant+ac...

http://lmgtfy.com/?q=site%3Anews.ycombinator.com+startup+law...

http://lmgtfy.com/?q=site%3Anews.ycombinator.com+business+pl...