Depends on weather or not you buy into string theory ghostshadow, if you do, it's not a universe, it's a multiverse.
time and time again in star trek, things change. It isn't always linear.
I think ramming the timeship was a suicidal risk, The time ship could have been armored better than the already fractured voyager, crushing it like an egg against a brick wall.
Janeway didn't know that ramming the timeship would fix things, she assumed it would.
Once again, the thought process leading up to the risk are interesting, but is the risk nullified if the timeline folds in on itself?
Worf isn't really taking risks, he views honorable death as a bonus. I think that does make him bolder, but not more likely to take risks.
The man drinks prune juice!