WAKE UP CALL!
1. Time is something invented by swiss ppl so they have an excuse to sell us clocks and watches, before the swiss did this we had the sun and the moon to show us "the time"
2. With the invention of time came stress. that's right, STRESS :wallbash: the #1 reason for burnouts and such. things like "OMFG i'm late for work" and "WTF it's X past XX already?" (replace x with any given number) I.E. not the best invention ever.
3. The possibility that timetravel will be abused is ******* HUGE! Approx 70% of the survivors of the 2nd world war will attempt to go back in time to kill the bastard (hitler) himself. Bloodwrath is imminent, killing the murderer of your husband / child etc. total chaos will emerge and the world will slowly but surely crumble into nothingness.
4. Who in his right mind would go back in time to kill his/her own grandfather?!?!?
5. EVERYBODY will try to go back in time to "prevent this mistake from ever happening". Chaos is, once again, very imminent.
6. (the first positive thing) you can try and stop the swiss from "inventing" time, effectively changing Timetravel to Whatevertravel.
7. yes indeed, there will be numerous time clashes (Timecop, Cycles of dawn, Groundhog day, etc.) In the end, the fabric of time will not be able to coop and the universe will end.
I hereby rest my case.

k:
Shoot me if you will.