If that's the case you'll need it every time you work. That will be quite a trouble then...
No, you'll still be able to have erections but you may find it slightly harder to get one for a short time after discontinuing it (only because it was easier to receive one with it).
I don't believe it is safe to take it if you don't have Ed. It is a prescribed drug, and might make your ability to receive an erection without the Viagra problematic. Once might be ok, but I would not advise you to do so. Perhaps you could just think approximately something sexy, or do something else to make you hard.
Kamagra only works if you're sexually stimulated - it doesn't cause spontaneous erections. So even if you do take it for your audition, it will only work if you're sexually stimulated. Therefore, there's no need to take it because it sounds like you're capable of getting an erection naturally, and if you want an erection during your audition just think about things that usually make you gain an erection.
If you feel you may want to try some medication to help though, Exact Pharma sell some medications for ED. Some young men are taking these recreationally to give their sex life a boost, so you may want to try them. You can buy Kamagra and other ED products @ http://www.exact-pharma.com
sounds go od..but being horny in a natural way would surpass viagra's effect...just dream of a awful horny and hot scenes....mmmm..it would be a great help _