Other than an 8/2 Towers/Mahi split, I had fun. Sorry if I tanked your rating with the terribly played rounds... The flank Fest on Towers especially threw me off in the one game against that Dynamo. My word.
You definitely seem good enough to get into S with enough time and effort, but there's no way to really watch a player's game while playing at the same time. You've got mechanics down, and your gameplan seems great on the offensive.
With that said, a few issues (that my play is also THOROUGHLY littered with):
I'd try Super-Jumping less. It's an extremely handy skill, but unless you're certain things are safe, swimming doesn't take too long. Towers is a difficult case here, because Jumping IS a lot faster. Just be extra careful with things.
The main issue I have with my own play, I also noticed you ran into a few times: not paying (enough) attention to weapon range. There's no reason to really get in the range of another player unless they forced a fight on you or you're flanking. Positioning, in other words. This is also, unfortunately, one of the most important parts of playing on the defense. :X
I can't really say too much more other than pointers, though. Don't feel qualified to really rate ones' play, being in a constant flux of A+/S..
Again though, I definitely think you can make it into S. Squad Battles are even harder than normals, due to a number of factors. And you held your own well. I'd definitely keep the positioning thing in mind. It goes a long way, especially in solo queue. Thankfully, you can even practice this in Turf Wars.
Mini wall of text over. ^^