I should have added, remember to turn off "antishake" or "shake reduction" or whatever it is called, as it may produce soft images when mounted on a tripod. Lord knows I forget most of the time. My infra red release works the same way, and if I had known, I never would have bought it. I use the 2-sec self timer most of the time and occasionally the electronic cable release. But I gave up on the cable, too much trouble to take it on and off when shooting on the quick with moving light. Got it caught once too often. I would not blame the tripod too much, my older Manfrotto is much heavier, and it still vibrates as does the lens from my observation. I had way less trouble with the older film Nikon heavy body and no electronic lens!
Re, mirror lock-up, my understanding is very few cameras have it, even the high end Nikons and Canons lack it. But lately I am not sure. What I use is the 2-sec self-timer (Pentax K10), which is almost as good. But it does consume power. So carry a spare battery. Many pros and serious amateurs that shoot other than people or portraiture use mirror lock up as a routine no matter what the settings, especially for landscape work. This was true in the film days as well, and every manufacturer had high end models with mirror lock-up, especially for the 645 medium format cameras. Lots of mirror vibration on those cameras.
Another thing some cameras are prone too, perhaps all, is extraneous light entering the viewfinder and altering your settings when in any auto mode. I place my hand over the viewfinder without touching the camera! It is not a problem for manual mode, however.