Been out for a while fidgeting with SSE levels.
On Sonic:
I'm also against speeding up any of his moves. Some viable changes that I think would help (and I am not suggesting ALL of these changes be made, just one, maybe two):
Bthrow kills at lower percent
or Bthrow goes at a lower angle
Dsmash does more damage/knockback to become a kill option with fsmash and bair.
Or dsmash hits with a lower angle
The earlier kill on bthrow (nothing drastic, a high percentage kill) would allow for a more reliable kill when your opponent starts getting to too high of a damage, if you've been unable to kill with fsmash or bair to that point.
Or, a lower angle on bthrow could allow for more constant offstage pressure. Dog on spring all you want, if you get your opponent off the stage multiple times per stock, there's a high chance you'll figure out how to hit your opponent with it (the key will end up being mindgames with it. Don't do stuff like jump out and drop the spring in their path--they're just going to airdodge or cancel the spring with an attack. Jump out low, try and bait an airdodge/attack, drop the spring when the dodge/attack ends, recover to safety. Stuff like that).
A stronger dsmash would just give Sonic another option. Dsmash's range isn't too terrible, and it's not terribly difficult to hit with either, since it can also punish spotdodges, and can also punish rolls due to it hitting behind him as well. Not to mention the charging animation for it looks just like spin dash, which could throw your opponent off sometimes.
Or, a lower angle on dsmash, with no damage increase. It would still kill a little earlier, but could also allow for more setups like what I mentioned above.
Respones to some other suggestions: As mentioned before, damage increase to fsmash does nothing because it's still just as hard to hit with. Same with bair. I don't support timing changes because I don't find it necessary, and think Sonic would be a bit too buffed if his kill moves came out faster. He can rack damage like a pro, and then can kill reliably? The more that metagame advanced, the better and better we'd see Sonic get.
As far as Sonic not having good approaches, I haven't heard any suggestion that would really help with that, even if kill moves were sped up. It's just a part of the character you have to deal with. I deal with the same thing with Falcon, except it's not nearly as easy for me to get quick punishes in. If you can't get inside, just be annoying and punish little things with dash attacks or dash grabs for minimal damage. Sonic does more damage in BBrawl, and just chipping away at your opponent (while remaining defensive and staying safe yourself), can get your opponent to high percentages in relatively short amounts of time.
Other stuff:
Ness's recovery is fine, as any experienced Ness main will tell you. Olimar's is also fine, and if you don't think so you need to get better with Olimar.
It can be Falcon timez nao plz?