To align images right - in the powercms 'edit content' screen, right click your image, select 'image properties', and from the 'Align' drop-down select 'right' (or wherever you want it to go).
Otherwise, the input text etc. inherits the css styles as applied to the page by your page's normal stylesheet(s).
You should certainly be able to upload .png files. The extension (.png) is listed in the default - as provided - 'WA_iRite/editor/filemanager/connectors/php/config.php file. (around line 113). If it's not there, you should add it.
Does the editor say it's been uploaded?