Ifi flash this will I still have all my data/apps
To increase your chances of the flash working properly, you must do a clean install. Meaning you wipe everything (except SD Card), thus you will lose all your apps and data. You can do a dirty install, where you don't wipe any of the data. But you run the risk of things not working as they should. (Other than the small bugs here and there that exist because this is a BETA.) I would recommend moving your photos to your SD Card, and then doing a clean install. If your apps and data are backed up to Google, they will automatically redownload with the data. Alternatively, you can use an app such as Titanium Backup to backup your app+data manually to the SD Card and resinstall them after the clean install.