There is sooooo much missing in my game. But on my Christmas List this year, I'd put a kick serve. A bit more topspin on my forehand would be nice, too, Santa.
Don't know that my opponents can really take advantage of those particular weaknesses...
I just can't take advantage of them.
As for your difficulty, Tidus, I think we all have it. Being able to roll over the top of a short ball, particularly to the backhand side, is difficult. That's one of the reasons I love to hit that shot to an opponent.
For a change of pace, instead of going deep down the line with it, try a short (almost/half-ass drop shot)...still down the line...and follow it in. Because most opponents are expecting one of the two choices you usually use, you may catch them off guard. Then, when/if they catch on, and follow their own shot in...blast one past them DTL again.
And don't worry about the "negative" aura of the question. It's a good one!