I watched a couple of your videos and here's what I think.
Your sleight of hand seems fine but I think you could work on your presentation.
You need to slow down a bit. e.g. in the biddle trick video it's like 'OK pick a card watch i'll lose your card, i know where it is etc. It's too fast in my opinion. You've hardly even lost the card but you're already finding it.
There should be offbeats in your performance that let everything sink in.
When I have somebody select a card and return it I cleanly show it in the centre then relax or take a step back, everyone else will relax as well. This allows for several things, you can do a control such as a pass with less heat on your hands and it also lets everything sink in and lets the audience prepare for the next stage of the effect.
These pauses only need to be very small, only 1 or 2 seconds but I really think they make a difference.
Watch this video of Wayne Houchin performing Indecent.
http://www.youtube.com/watch?v=x7YkF8WOYns
After he spreads the cards over the bag he pauses for a couple of seconds to build up tension and so the audience can really understand whats happening.
I would also recommend having a look at The Devil's Picturebook by Derren Brown sometime, he has a brilliant understanding of the 'beats' and pacing of a performance.
These suggestions are purely my opinion and what works for me, I don't know if it will help you but it's something to think about.
Makes it THAT much more fun to watch