I have read a couple of articles regarding making sure that your permalinks are SEO friendly. Little point in creating great looking website if in time you cant get it to No1 on Google for relevant keywords.
That being said I have gone into Settings>Permalinks and have changed my Permalinks from Default to Postname and then gone into each post / page to ensure they match that relevant post / page and link accordingly.
If you have Post Name permalink structure, when you move your /dev site to root, the /dev in the URL will automatically be stripped off. You don’t have to actually move your files from /dev to root in order to take it on root. Just change Site Address (URL), and copy index.php to root. Then change