I haven't read the whole topic but I'll give you some tips with DK:
DK has some seriously good throws; although I don't use his Uthrow or Cargo Ftoss very much, the rest of his other ones are great. A good combo you can use is Dthrow -> Ftilt; this works good for very low %, and the smaller the enemy, the faster you'll throw them, and the easier it will be to Ftilt them. Bthrow is basically DK's best throw, KO wise. This can easily kill an opponent if thrown from the edge of the stage at a high enough %, so use it a lot. Ah, now we get to the cargo throw; what an excellent one. Generally the best Cargo toss you'll want to use is Dtoss to set up several traps and attacks. A good example would be Dtoss -> Fair or Dair for a spike. This is the most common set up. Another good one is Dtoss -> Bair your opponent away. Finally, Cargo stage spike is your friend. I once told someone that they should always do it if they're near the edge and the enemy's at a high enough %, but like bigfoot said, Bthrow sometimes is the better option, however you definitely want to learn to utilize CSS whenever you have the opportunity.
DK has amazing tilts. Ftilt has great knockback and Dtilt is excellent for tripping the enemy and to set up some devastating follow-ups. Generally I like to do Dtilt -> DownB. Try it; it works wonders. Utilt has amazing range that can hit the enemy pretty far from behind, and you can sometimes juggle your opponents with it.
Don't be afraid to sometimes use his dash attack. It has some lag in the end, but if you use it sparingly enough that you can catch the enemy by surprise with it, it works wonders. It has
really good knockback, even at very low %.
Learn to stall with UpB on the edge during moments where the enemy is pressuring you on the edge too much to safely get back up. You'll want to do this quickly and efficiently by pressing the opposite direction you're facing as you're hanging on the ledge, then immediatly pressing UpB. This is the quicket way to ledge stall. His ledge attack at low % is very good too, and has great range and speed.
Learn to spike very well with Fair and Dair, depending on the situation that's suitable for either one of those attacks. Sometimes I like to Fair as I get back on the stage if my opponent decides to jump and attempt to edgeguard me. This won't always work, obviously, but sometimes you'll catch them with it and spike 'em good. I've managed to do that several times. Dair is the safer option, and almost has just as good knockback as Fair. As for Bair, I think you're doing well enough with it as it is. Definitely one of DK's best approaches. A favorite use of mine for Bair however is to stage spike enemies. Usually I do this if they're stalling up and down on the ledge, and I run off the stage and immediatly Bair in hope of smacking them onto the sloped ledges to stage spike them. This will work on any stage with sloped edges. Learn to use Uair as well. Uair definitely has decent KO power and it's good for catching enemies by surprise. You can also hit enemies with it while ledge stalling if they're close enough. Nair is a good move, albeit a tad situational. Sometimes I use it when falling down or in the air.
DK's smashes are amazing, and some of the best in the game. Generally I like to use Fsmash to punish rolls, air dodges, and any enemy that attempts to recover back on the stage (a good example with Fox is if he uses his SideB and you position yourself so that he lands right in front of you, and you Fsmash him in the face). It has amazingly good range and almost just as good knockback as the super punch. Dsmash is probably the most common smash you'll want to use. It has a HUGE hitbox and can actually hit enemies from above, even if they're on platforms (Ex: Battlefield). This is a smash you'll want to use often to punish enemies. Usmash is probably going to be your least used smash, but do use it when you can! The best time to use it for example is if an enemy is above you on a platform. Other good uses are to punish air dodges and if you predict the enemy will jump above you from the edge.
DK's jab is actually pretty decent. I don't have much to say for this move but you can juggle enemies a couple times with it at very low %. You can also jab cancel and follow it up with a tilt. I commonly use A -> Dtilt -> Ftilt.
Finally, we get onto his specials. I don't think I need to explain the super punch much to you. This is by far DK's best KO move and you'll definitely want to keep it charged at all times. You can charge it in the air and press the dodge button during charging to stop the charge too. UpB is another move I really like. Use this move and its super armor frames to your advantage to rip through your enemies, and use it for punishing spot dodges and rolls as well. DownB is an amazing move, probably my second-most used DK special. This is a great move to punish rolling and spot dodging, and as I've mentioned before, Dtilt -> DownB works absolute wonders. This move can even outrange Snake's tilts, so consider that the next time you fight a Snake. Finally, his SideB. SideB is a bit of a risky move, but oh boy is it awesome when you hit someone with it. You'll want to use this mostly for punishing dodges. You can also spike people with it, but that's pretty risky and they don't really go too far down so I don't really use SideB for that.
tl;dr You'll love DK.
