If you're happy with, then its a good tree...
However, (and I'm going to be what some might call a jerk from here on--so stop reading if you don't want to hear it)...
what you've basically done is forced branching into unnatural positions, instead of doing the required pruning to get a more natural looking tree. Take a step back and REALLY look at it...does it look like its shape happened naturally? or does it look like it always did, only on a slant?
Windswept is not an easy style to do, even for well -experienced bonsaiists. Like literati, the style is sometimes a fall back for beginners with difficult material.
Your initial ideas for an oak style were correct with this material. It was a pretty decent start on that style too. Forcing a style on a tree that isn't initially suited to it winds up looking odd., not to mention the tree can also suffer, since it doesn't really grow as its being forced to do. Boxwood don't like to have their branches inverted. Small branches like the one on this tree can also be easily damaged or killed with aggressive wiring. They back bud very easily when hard pruned, however. That makes it effective with a clip and grow approach. The tall boxwood below was developed from a stump dug from a hedge. It's trunk lends itself (like yours does) to a more upright "Tall tree" image. The other one (a kingsville) is an "old live oak" image. It has a tiny single trunk that had many branches coming from it. I used what was there and didn't try to make either do something they didn't "want to do."