So I've resisted posting here for a while, as I still have yet to clock a single minute of brawl play, but for the sake of the discussion being continued I'm gonna point out what I've noticed, videos only.
Positioning: Watch
http://uk.youtube.com/watch?v=c3qmrB4DUI0 Woker vs Anji (link). Notice how Woker ALMOST ALWAYS has his back to the center of the stage, and is most the time only hanging out in the middle area of the stage anyway. Obviously this is an advantage, but a particularly important one for Oli due to tether issues. Most importantly, and this was the biggest issue i saw in DSF vs Gimpy's posted match, when Anji moved in to challenge the middle positioning, Woker did not retreat, he made use of Oli's closer but still great range smashes and grabs. DSF landed something like 4 grabs, 3 smashs, and a weird dash attack or jab early in the match total on Gimpy, and most of this were in that middle section of the game where he was fighting back. Whether gimpy is just too fast to touch is not the complete issue though, what gimpy did that really beat DSF in my eyes was discourage that closer combat play all together, DSF commonly gives up middle positioning, retreating throwing pikmin or semi threatening spaced aerials. Take the middle, and most importantly once you've got it, Fight for it, if they come in smash/grab/dtilt->fair away (loved it when i saw it in the woker vid) and don't stop till the middle is yours again, if they want to camp on the outside thats great, Oli can play range all day, but he CAN'T give up the middle.
Ledge Guarding: This is still sortof part of positioning, but Olimer players must be careful in choosing when to edge guard, a lot of the positioning troubles I've seen in solid play come when ledge guarding situations get sticky, and suddenly Oli is taking some hits way out on the sides and forced to play recovery games.
DI: Its been mentioned, and I can't claim to have watched closely enough to be able to tell just how effective the DI is in each video, but as it was written above, olimer should DI up like a madman, its vital to survival. Oli isn't the best character in the world when above his opponent, but its better than keeping low and having to use a tether recovery. Also either I'm blind, or I have yet to see an olimer player use the air dodge increased DI yet, or at least not as fully as i expect it could be used.
DownB: I know I'm one of the weird ones about this, people with the game have explained its difficult to time and the super armor frames are so short that sometimes it can't fully absorb an attack's knockback, but I still see it as super armor isn't something there by accident, especially since they even mentioned Ike's on the dojo, I just have to feel theres something there. Ike has super armor, and as seen in the Ryan vs Andrew(ike) videoes at PkmnStadium Ike is also fairly gimpable. Maybe i'm giving sakurai too much credit, just at least until i can play the game and determine it hopeless myself, DownB super armor is like an itch i can't scratch especially as people mention Oli's poor recovery. Its like the turtle post far back, but less... turtle like? If you don't have to recover...
UpB: Last thing I promise. In some videos it seems the angle latched by the ledge is weird, I'm not sure the video hopefully i'll find it, but I believe I saw someone's UpB grab the stage while still considerably above it. In another video however a similar situation the UpB went up as an attack not auto aimed at all, despite the ledge being open. Now I can't remember the specific videos, so there could have been some differences in how far from the ledge they were, but just throwing it out there to people with the game, perhaps latch is to a small degree aimable like pit's arrow, UpB but like if your above the stage and press down it'll go to the ledge, keep the control stick up it'll go up. Maybe UpB favors targeting the ledge, but if you move the joystick right it'll default to the 45 degree. This would only matter if the 45 attack could first attack the ledge hogger and then, maybe if theres an extra pikmin than needed in length, also grab the ledge.
So anyway theres my two cents, can't say I didn't give your money's worth, just things to look focus on and look in to. Gimpy and Hitaku if your reading I really enjoy your guys input from non Oli points of view. I guess as closing Oli players lucky enough to have the game, if recovery is an issue see if you can't work on the positioning and DI details I tried to emphasize, I haven't seen a video yet that has accomplished both of those things completely yet in my eyes, although echo and dsf certainly do well with it most games, see their videos for more examples. We'll work through/around this shortcoming of Oli's yet.
-True