How insecure can one be about what type of bowler one is.  What does it matter how we classify you?  As mentioned, your elbow is bent too much.  Your swing slot moves away from your body.  You are way off balance as you release the ball.  Why don't you post this on bowlingchat.net and let Jim Merrill tell you what you are or aren't?  Correct those things and you won't have to depend on revs to score.     

Elbow has nothing to do with balance.  If that was the case; Barnes, Robert Smith, and others with bent elbows would be off balance.  A.  His shoes appear cheap (could be wrong).  But his slide never stops; almost as though he has Easy Slide on the bottom of his shoe.  B.  When he slides, his slide foot is pointed at the 7 pin while his shoulders are pointed towards the 10 pin.  His lower body is not working well with his upper body.  C.  His left arm is almost tucked at his side and not out away from his body to help with balance.  D.  I think he starts too far back from the foul line.  If he started a little closer to the foul line and shortened his steps, that could aid in helping with balance as well.  Those are all the things I notice.

. Rev rate is around 400-430, speed around 17.5-18 mph on average.

Since stroker, tweener, and cranker are basically defined by rev rate.

Here's a couple charts I've seen:

< 250 stroker
250-400 tweener
> 400 cranker

------------
<240 Stroker
240-360 Tweener
>360 Cranker

So with a Rev rate around 400-430, that would be cranker.

A Rob Mautner post:
Today, stroker, tweener, and cranker is defined totally by rev rate. Many people still believe that the line that bowlers play is indicative of their style, but it's no longer the case. It's purely rev rate. To show you how rediculous the whole concept has become, Walter Ray is a tweener, and Pete Weber is a stroker (based purely on rev rate off the hand - Pete's voodoo roll saves all his revs for the back end)). If nothing else, this shows that trying to define ourselves as bowlers by using arbitrary labels is counter-productive. As far as ball reviews are concerned, learn the numbers and apply them to what you know about your own style and what works for you. I will telll you from my own experience that at least 90% of bowlers who tell you that they are tweeners are really strokers. All the titles do is muddy the waters, IMHO.