Guild Wars 2

I know there is a World Events schedule at https://www.guildwars2.com/en/news/the-megaserver-system-world-bosses-and-events/. But is there one for the bosses at Orr (e.g. Risen Priest of Balthazar, Risen Priestess of Lyssa, Statue of Dwayna, Temple of Grenth, Temple of Melandru)?

I am going to have very limited time soon, and I won’t have the time to just wait around anymore, so it would help if I knew when these bosses are scheduled to appear. Thanks.

Here’s something I don’t understand. I played my lvl 35 warrior and lvl 52 elementalist in a dungeon just ONCE, EACH. When I tried to enter the dungeon again with either, it gave me a message that I’ve joined too many groups.

This led me to think this limitation is account-wide. But when I log in as my lvl 80 guardian, I am able to get into a dungeon.

So does this limitation on joining dungeons apply only to characters of a certain level range? I want to get an official and definitive answer on this if I can. Thanks.