Ah Blade Dancer. A solid idea for a Flash build. The bad, you can't get it until 9th level. Also, it's 3.0 material with some kinda silly stuff. The good. The movement bonus is just a change to your base speed, technically, it's not a bonus at all. So it stacks with anything. Also good, you will never, ever trigger an Attack of Opportunity from movement again, due to getting a +10 bonus to Tumble at first level (this eventually goes to +30, I said there was some silly stuff) and you can take 10 on Tumble at any time. Given your probable Dex at the level you get this, you can automatically move through the threatened areas of anything with a CMD of less than 38.
(I have no idea what the designers were thinking with that Tumble bonus in 3.0, there was literally no use for it as the highest official Tumble DC was 25, you never, ever needed more.)
One problem I see with this is that Flash really ought to have some way of getting a LOT of attacks. Swiftblade does sorta get there eventually, but it really needs some help.