Killing Gerdur shouldn't be too hard and if you did shouldn't be too much of a overall problem. She is not realy a important NPC in the game.
there are no lions
no if you try they kill you
You need to kill the old woman at the orphanage in Riften.
Yes but only if you kill them.
They live forever unless you kill them.
You don't kill him, you have to make him chase you into the keep (right behind you.)
Try a calm spell.
You take the game out, then put it into your computer. Open up minecraft, go into creative mode, get a cow embrio, and download into skyrim. There will now be a cow in skyrim. The get it, you have to kill the cow in whiterun, put the other one in the kennel, and then kill all of the owners of the cow. If you succeed at this, you should be able to take the cow to mount doom in mordor. From there simply kill golum, and the cow will be yours.
they never stop coming back, so you can kill as much as you want
Just like children and other NPC's You cant kill it but if you hurt it you will gain a bounty
Kill a Stormcloak officer.
I hope not! Don't they KILL the dragons in those games?!?