From Boom's description of you, you do sound a bit predictable. You said yourself you Fair to Dsmash too much. Basically, use those little tricks every once in a while, but build up a larger arsenal of mini combos and approaches so you have a broader aray of options at your disposal. You mentioned you liked the Dthrow to utilt combo, encorporate it into your play. Definately make sure to grab. Boom said you almost never did. If you hardly ever grab it doesn't matter how unpredictable you might be, your opponent will know they can just sheild and then grab you during your afterlag.
Also make sure to know who you can chaingrab, and which method is better on that character.
In addition, you said you didn't know many edgeguarding techniques, check the pika guide here, it has a couple examples. There are also a few old threads you could look for on mini combos.
And my biggest piece of advice USE THE QuAC! It is your friend. Use it to approach, to move, to cancel out an opponents attack and then use a tilt before they know what happened. Galax once wrote a long report about how important QuAC proved to be for him in one of his tournies, idk where it is, but you should ask him about it.
Hope that helped a little. =)
Wont be able to play today, hopefully will soon.