As this is the Requests and Feedback forum this answer may not be what you are looking for but here goes.
Please someone tell me why the text sizing option is gone
WordPress 3.8.x didn't have any font or text sizing capability built in. That was always been added via a plugin and you can get it back by installing TinyMCE Advanced.
I just tried it and easily added a "Font Sizes" drop down menu to the visual editor in WordPress 3.9.
and why I cannot place image borders any longer.
As to the image borders I believe that that may be taken care of by another plugin soon to be released but I do not have specifics for that myself.
Edit: Well that was a short walk. Try this plugin for those image options.