Shuki made a great point about misread serve returns. Just make sure you are in position and when you smash , smash with a firm wrist and compact follow through, you might need to smash twice or thrice but thats okay , all you need is to figure out the correct racquet angle to smash those high chops ....
Now, regarding the other point you are making, IMHO don't change your serves or serving strategy . You definitely need to work on the other serves, the height and what not, and make sure when its half long, its short half long not long half long
.... short meaning, it should or at least should appear to bounce right near the edge again ... otherwise it a sure fire way of getting a strong loop back , when you will get in to defensive.
The way I have tried to resolve the third ball opening problem is is to have one regular practice partner, one that is slightly above your level or somebody who can adapt and start returning your best serves. You have to make the sacrifice that you might end up getting beaten by this particular guy more than others but then you will also learn to improve your third ball attacks because he will start getting them back after regularly playing you.
I could not find out another solution to this, just because I also depend a lot on my serves to win me points ... but I also want to have a strong third ball , so that I don't get stuck on the later stages of a match when my opponent starts getting my serves back, this I have seen happening pretty frequently to people who depend on third ball attacks...