Are there any office spreadsheet editors that have trouble editing
standard CSV spreadsheets?
Yes, a widely used non-POSIX office suite from 2007 has considerable problems
saving a CSV correctly.
Are there any browsers that don't support the SVG image format?
SVG is supported by nearly any graphical browser available.
Notable browsers incapable of rendering SVG include Dillo (all versions) and
MS Internet Explorer (all versions, can be remedied with plugins).