I sincerly hope that you weren't serious when you said that you vote 0 when someone states that they submit their first flash - those users are excited about showcasing their content to an audience and it is completely normal to state that it is their first flash, also to make sure that the viewer doesn't get too high expectations. Is it trying to get a better vote that way? Maybe - but encouragement for promising new talent never hurts - after all that is what Newgrounds is all about.
If you just hit 0 when you read "this is my first flash" than you are just as unfairly unvoting as someone who votes 5 without watching - after all you did the same, you just hit a button postioned slightly left.
How about you watch the flash, give then a fair rating and maybe even a review instead of shying away new artists, something that Newgrounds needs at all times. Savewhores are driving the flash portal into the ground, but becoming elitist and all mighty is as dangerous. We want fair votes, not a guideline for what to vote 0 on without watching.
As guideline for paying attention to the flash it is fine - though every flash should get equal amount of attention. After all, a flash can be 100 Mb big and still total trash. So no matter what, there is basically only one guideline: watch, and then vote what you consider as fair.
Cyberdevil
I just tried searching for 'teaser' to see if it's true (that teasers are shit), it turns out... submissions with 'teaser' in the title are usually all but shit. That doesn't say much about the overall trend in such a content type though, but there's no easy way to filter that.
About submission size btw, back in the day the biggest submissions were often the crappiest ones, using filler content to make them look bigger. I'd think that still applies to a nice slice.