Max out Sweeping. Higher skill level = more time to use your skills before the swept area fades. 1 sec per level may not seem like much but you’re not going to get more than a couple skills out in a tiny 5 second timeframe at level 1. For example, with lv5 Sweeping my Miko can just barely squeeze out six groundspells before it wears off.
If you don’t need clap, I’d recommend Gohei Lv1, Sweeping Lv5, Hamaya Lv5, Kagura Lv4 (or skip and put points into Gohei if you don’t like Kagura, but Gohei is fine at lv1).