You've taken a Hoverfly, Greenbottle and a type of Ichneumon wasp.
The first looks a bit noisy - think the ISO 2000 is pushing it. The last is better at ISO 200. Think you may be able to go somewhere in between ISO wise. Last is nicely done in natural light.
You should be able to get closer with that 100mm lens. Also to aid sharpness with moving insects - especially as you get closer, I'd recommend using a flash. And diffuse it - check the macro rig thread for ideas on lighting. Even if you have no speedlight u can always "pringle tube" the pop up flash on camera as a starting point.