Spiffy-Gonzalez, the same argument you made against phasing (fusing with an object) could be made against teleportation. If you actually think about it, the fusing problem would be much more dangerous for a teleporter. He or she would have to know the exact place where they would want to teleport. Going off memory is a risk I wouldn't want to take. There are bugs, birds, cats, dogs, people you could potentially fuse with. Not to mention the other countless stuff like vehicles, bikes, store signs, signs in general, buildings, etc, etc, etc. The world changes pretty fast. Can your memory keep up? Next time, try to stay clear from the low hanging fruit.
Reece, that would be far more dangerous as a speedster than a teleport. The odd chance of a bug being there is far less likely than one out of an immeasurable number of molecules colliding with one of the cell bars' molecules. And all of this is assuming that it's car possible. I understand this whole concept is based on pseudoscience, but just because super speed is suddenly a possibility does NOT mean that phasing through an object is suddenly possible, and as I said before even if it is it is still FAR more dangerous than the odd chance of a bug being somewhere at the wrong time (which would also assume that the exact type of teleportation is simply transferring your matter from one place to another. Which it could easily not be.)
And super speed is just that, speed. It bends the laws of movement. If you were to move faster you would not be able to tell where you are going and easily crash into a wall if you were going too fast. Worse yet is if you could, because that would mean that your mind is going fast. It would deteriorate far faster than the average human being. And if you could bend time to go slower this technically making you faster you would still age normally, thus making you die faster.
Things like speed force are out of the question. Flash does not run fast, therefore it is not super speed. A force bending the laws of time is far different than you superseding the laws of movement.