Here are some questions you might asked yourself over time. Also some nice Tips and Tricks are listed here, which you may find informative.
There are a few options: The right-click context menu in the Inventory (playerbook_inventory) reveals ignite/thaw, which will ignite something or thaw icecubes. You will need a flint & steel $ARCH/light/flint_and_steel.base.111.png for this to work!
An alternative would be to use the mark (mark in command) and apply (apply in command) commands like this:
mark icecube apply flint and steel
If you need to something do this often, I recommend using the Bind Recorder (binding_recorder).
Most likely, you don't have accelerated OpenGL support. Try to find a newer driver, or a driver from your hardware vendor, that features OpenGL support.
If this is not an option, the following Setup options reduce the load and will likely make the client playable with software rendering (it will still be slow, though):