Piano Forum

I'm doing my first kinda event thing for piano. It's a junior festival. Boy, my blood's rushing already.
Anyway, I'm going to be performing a required piece and a solo of my own choice. Now I'm not worried about the required piece, but it's my solo I'm pretty bent on.
I'm doing Muzio Clemente Opus 36 No.1 Movement 1. I know it sounds easy but I have to bring it up to performance level and unfortunately I don't think I'm doing too well. Any tips?
Let me talk about my problems on the song, too. Right at the beginning of the song, when the left hand descends to piano my hand has a weird time staying in beat. Like it could be the first notes are too fast, then the last 2 are slow to compensate for the tempo. Something like that.. It's really annoying me to the brink of frustration.
Also, when I do play the notes on bass, my hand always stays on the keys. I never lift my hand and I think I should. I watch all the performances on the song and seem to see everyone lifting their left hand after playing a note.
My staccato isn't as crisp as I want it. But if I try to make it more crisp, the dynamic goes softer which is what I don't want. Please help a amateur out (and yes, I finally spelled it right )