You really think that could take a Pokemon out? Weather Ball doesn't work, in rain Weather Ball will be water, in sun fire. Unless you have your own weather it's not easy, besides in weather Weather Ball doesn't take advantage of Technician, and outside of weather it's a puny normal type move. HP Fire again doesn't take advantage of Technician, and Leaf Strong hits way harder than Tech Magical Leaf. Synthesis and Sleep Powder again don't take advantage of Technician but they are moves it should know. Overall, you could have a much better Roserade with Natural Cure tbh.