I agree it's kind of hidden, but if you go to your activity page, you should see all of your suggested edits: if you click on the phrase "suggested edit", you'll get an overview of your suggested edit and what happened with it: whether it was approved or rejected, and if it was rejected, a reason why.
To answer your specific questions:
That's probably a design bug and ought to be fixed.
5 is too many. I know I rejected 4 of yours, and when I looked at your other suggested edits, I saw at least 2 more. This isn't explained very well, but keep in mind that the tag wiki and the tag wiki excerpt count as two separate suggestions: so, when you suggest edits to both on 3 tags, and they all get rejected, the system counts it as 6 separate rejections and blocks you from suggesting any more.
And now to why they were rejected: like I said, I rejected some of yours. The reason why was that your suggestions were commentary about the game. For example, here are some of your tag wiki excerpt suggestions:
Kirby's return to power-copying platforming goodness on the Wii.
The third game in the Smash Bros. series, and certainly the most polarizing among fans.
The sequel to the N64 smash hit, SSBM is the quintessential GameCube game and is still played competitively on a massive scale.
Your suggestions for the full tag wikis were also of similar tone. To quote the Dude, what you're suggesting for tag wikis—the thing by which everyone on the site uses to determine whether to use the tag or not—is you know, just like, uh, your opinion, man.
Tag wikis are not commentary. They're not there to tell everyone about why the game is great or what your thoughts are about it: they're there to tell people what exactly the tag is about and when they should be used. Take a look at the other tag wikis for games like skyrim, minecraft, and civilization-v:
A fantasy action RPG from autumn 2011 by Bethesda Softworks, it is the fifth game from the main line of the "Elder Scrolls" series.
Mojang's exploration and survival based sandbox game in almost endless, procedurally generated worlds.
Sid Meier's Civilization V is a turn-based strategy game encompassing all of human history. Players attempt to take a fledging civilization from 4000BC to modern times and lead their civilization to victory through domination, science, culture or diplomacy.
Describes the game, doesn't add commentary about whether the game is good or not. That's what a tag wiki should be.
As an aside, I noticed starcraft-2's excerpt is like what you've been suggesting, and really ought to be changed. From the looks of it, what's there now is actually an improvement from its original form. I just submitted a suggestion to fix it so it matches the others.
