Do to the low price, most people don't have an reservations toward opening them up and messing around. I didn't like holding the button, so I put in a different switch. Didn't like the loud beep, swapped out the beeper, with a pager motor, so it vibrates. While I had it apart, messed with the little trim pot, to fine tune it. Broke it, replaced it with a 2k pot, roughly, only thing close I had, that would fit in the PCB holes.
I don't know about protecting the switch, for the price, I didn't really care. Works good though. Just got a Propointer a couple of days ago, it's got some extras, but not as big a jump as you'd expect for the price. Wouldn't buy another one, if lose the one I've got. The Centech is really more my speed, I like tweaking things.
You the 'Search' button, there are several thread about the Centech, if you got a soldering iron, you won't have any problems.