Moving from 7.30 to 7.35

Hi. I begin to test the version 7.35.Because I want to use more the fluid options.

I Begin to move a theme create with 7 30 version. The First result a white screen with nothing. Then I create a new subtheme based in 7.35 and begin to move Less code from the old theme, but I have some issues:

1- Grunt Stop to work So copy the grunt.js and package.json and bower.json from the 7.35 and work but...

2- I add all this code to grunt.js to work with grunt watch

module.exports = function(grunt) {
  require('jit-grunt')(grunt);

  grunt.initConfig({
    less: {
      development: {
        options: {
          compress: true,
          yuicompress: true,
          optimization: 2
        },
        files: {
          "css/style.css": "less/style.less" // destination file and source file
        }
      }
    },
    watch: {
      styles: {
        files: ['less/**/*.less'], // which files to watch
        tasks: ['less'],
        options: {
          nospawn: true
        }
      }
    }
  });

  grunt.registerTask('default', ['less', 'watch']);
};

So....

The way I do it is correct or there is a better way to move to 7.35 version?

If doesnt exit, Could be this issue a first step to create a page with documentation?