is your region strong? Is it necessary for you to actually win tourneys to be happy? or do you enjoy the game enough that going to a tourney, spending 5 bucks and going out 0-2 bothers you? realistically if you train hard I think you could guarantee top 8 at the majority of locals in any region, but I feel like most people have little grasp on what the meaning of train hard is. I consider myself to be a working man that is mostly retired from melee, yet i still practice more vs comps than most people practice total(it's relaxing to visualize spacings, practice movement combos or edgeguarding on comps. That said, I'm probably the only person that has memorized ways to get the opposing comp fox to firefox from specific positions. Still can't practice it all either).
started to post all sorts of things that would help, then deleted it all. Being realistic, you will not be able to handle top level falco or sheik play. Bum didn't face much sheik when he did so well, and the falco game has developed a lot since then. It honestly wouldn't surprise me if a DK managed to take sets off of fox, marth, ICs, or jiggs, but falco, sheik, and peach seem extremely difficult. Still, with a secondary, it would be very possible to do well with DK, but honestly playing a secondary makes it harder to master new skills with a char, so it makes playing DK at all seem very much a waste of time.