Unless you play a fairly high standard there is no real need to play over the top. If you don't middle a drive then if will be safely on the ground but if you don't middle a lofted shot you are in real danger of being caught. You should focus on timing the ball on the ground and watch the singles turn into 4s. You will get enough full pitched bowling that driving should be your main scoring shot. Shorter bowling, if you're not confident you can play it, should be left or blocked because they're unlikely to bowl everything short.
If the captain says you aren't ready to play in the team then you should prove to him that you can score runs sensibly, not try to impress with fancy shots over the top.
A steady 50 will always go down better than a rapid fire 25.