I'll refer you to /blogs/ArlanfromAntigua/2016/09/03/sharing-with-everyone-public-in-survey123-may-be-coming-sooner-th... - this discussion pretty well sums up the roadmap for public surveys. With regards to opening surveys in the web browser, this is currently supported at survey123.arcgis.com for surveys authored via the web site. Surveys authored (or updated) by Survey123 Connect can be too complicated for the current version of the web form, but we are planning to address that in future releases.
