I'd also like to add something that I think a lot of newcomers miss: This site isn't a repository for just any old TAS that anyone makes. If you want a run published on the site, you have to beat
all existing records, including runs only seen on Youtube or Nicovideo or Youku or, hell, even other TAS-based sites since apparently those exist.
Your first attempts at any run will almost never be good enough to be published. That holds true for damn near everyone on this site: Even experienced TASers miss some things the first time around. At the very least, I'd suggest trying to improve your runs immediately after finishing them instead of submitting them to the site... well, not that you
can submit to the site at the moment, but that's subject to change if you take the time to hone your skills.
And honestly, I'd also suggest maybe taking a step back from SMW at the moment. You seem to know some of the tricks and mechanics, which is always nice, but the game's been optimized to death by the community and it'd be near-impossible to get anything published at your current skill level. If you really want to TAS SMW, you'll have to put in a hell of a lot more effort and start getting active in the community and learning from the people who have been TASing the game for years. Just ignore the (thankfully few) bad eggs who will publicly ridicule you for not knowing certain speed tricks.
Try something more simple for now:
Here's a sizable list of currently published runs that you could try to improve. Pick a game you know, study the current run, revive the game thread on the forums and take a shot at it. Try to beat the first stage faster than the published run, then try to beat the first stage faster than that, then post a WIP and see what people think.
The most important thing I can say is this:
Stick around. Don't get discouraged by a rejected run or someone telling you that your movie can be improved. We have quite a few active people in the community that took a while to settle in and improve their skills, and it's always really refreshing to see other people like that. As long as you keep working, you'll keep improving.