Hehe, man I hate Sonic dittos XD
As for some advice, since Reo asked me to help you:
You seem to know his main techs, but you're missing on some of the basics XD. You seem to have some weakness killing, although I was playing Sonic and I know it can be tough to land a kill on Sonic. Try to mindgame your kills, some basic tricks I did on you should help, like running passttt your opponent, and then fsmashing, or stopping right before your opponent and smashnig. Charging fsmashes is basic.
Work on some mindgames overall. You used ASC and shield cancel alot, but not as mindgames, you kinda did it just because =P
The othe rkey point I saw you lacking is a grab game. You could land grabs, but not really chain them and such. Work on that =P
I'll be glad to play you some more =]
Ohhhh, and for the wall jump, just hold towards the stage after you jump.