Right I'm reluctant to post this as I know the TA Ratio will drop once others find out this little 'cheat' however for the greater good I'm posting it anyway!
To get to level 7 in action mode you need to take advantage of the fact that time bar doesn't diminish whilst the gems are in motion/animating. Use this to your advantage to constantly change gems (regardless if they match or not) so that they're always moving, you can then look around the board for gems that do match.
I was able to get to level 9 and some ridiculous score.