Look at the scales. To create a usable black hole (as you rightly said, too small and it would evaporate immediately) you need a significant mass. To be able to control it, you would therefore need quite a lot of charge because of its large mass. And the repulsive force when trying to feed in more charge would increase with the charge you are trying to build up - making this an extremely difficult task.
Also, the physics concerning charged black holes is far from understood
- it is quite possible that with enough charge, the tiny black hole will rip itself to pieces. Of course, we'd learn a lot from such an event!
Particle colliders use much smaller and lighter particles (even the "large hadrons" are not that heavy), thus they can be controlled with smaller charges on the particles. And the collisions are often done against neutral targets, or even opposite charged targets (such as electron/positron colliders) to avoid the electromagnetic repulsion.
No, there is a huge difference. If I "believe" something, then I know it to be true - always and unchanging (unless I later lose that faith). If I "assume" something, then I willingly and temporarily treat it as true, knowing that it is not necessarily true, in order to learn something else.
The point is that different scientists (and engineers, and other technical people) can build upon each others work - even if some of the parts they rely on change in the future.
Again, this is not something new - nor is it a problem for practical work in maths. It /is/ an issue to philosophers, and it is something that many people have discussed at length.
I am not "starting to catch on" - I am merely stating some basics about science that I have understood for about three decades. But perhaps you are starting to understand what I have been trying to say (or perhaps I have started saying it in a way you understand).
What other forms of "evidence" do you suggest? I am not suggesting in any way that science can explain everything (is there a good scientific reason for us spending time on this discussion?), nor that we should go through life like Mr. Spock. But science is our best tool for understanding the workings of the universe - I know of no other that gives real and useful results (other than giving nice names to the days of the week).