Regarding the first issue, a pretty simple fix would just be to allow avatar creators to tag whether a given avatar is visible to search queries or not.
As for avatar ripping, it’s already ridiculously easy to rip an avatar; there are literally websites that make it possible to rip the vrca file from the servers without ever even booting up the game. A search function is hardly going to make the problem any worse than it already is.
When it comes to crashers, even with a search function, they aren’t as easy to find as you might think; no one is going around openly labeling their crasher avatar as a crasher, you’d have to already know exactly what avatar you’re looking for. And it’s not like it’s that difficult to just make your own crasher atm. So, again, adding a search function is not going to make the problem any worse than it already is. Removing the anti-crasher mods thousands of people relied on to combat crasher avatars? Now that does make the issue worse.