Do whatever feels most natural to you. It won't necessarily help anything. What's important is to keep practicing, and you'll suddenly pass all the songs you once failed.
It doesn't matter if you use a ball mouse or whatever to play, it all comes down to skill.It ain't gonna be like a stroll in the park if you continue with the tablet but with training you will see results.
Your playstyle doesn't change how good you are. You either practice and get good or you blame your equipment and suckit affects how good you are.. well in my case yes. before i had a proper mouse pad, i could only play normal. after i bought my mouse pad i could play hard or even insanes. (Razor Goliathus) it makes my mouse movement smoother and it makes it much easier for me.