FL's tools are sufficient in making decent trance or dance- trance was made with experimenting with known presets (for example, Vangelis' strings and choirs from the 80's would later be used and modified by tweaking them.) It's all about tweaking the instruments and knowing a little about sound theory (you learn that stuff by fooling around and reading about articles about the knobs you are using.)
Fruity Piano might be weak - but hey, too many artists made hits using the Korg M1 piano so hey, it's not exactly worthless.