I think the Golden Fazzbear is intentional since it happens in the real game, since you cant actually crash the web version I belive it just doesnt allow you to go back until you restart the page.
The crashing is intentional. There has been a revision in the design so that you can return if self-summoned in the upcoming update.
Yeah that's only there to scare you, according to the wiki. Just spam it a couple times and it should be fine.
