Returning Asking for Advice on servers/class

[ImminentVictory]

Hello guys! Played for a few years here back in 2008-2014 when the project was named differently. Recently I decided to return to this game and play it casually for pleasure. I am looking to play 70% PvE, 30% PvP on the WOTLK, but I see the server has a few different options. As I understand it, I have to choose between Frostmourne(dedicated PvE) and Icecrown servers. As I said, I dont want 100% PvE only, but I am afraid that on Icecrown it might be 100% PvP. Can somebody give me an advice what I should choose? I love doing dungeons, raids and such, in PvE, and I will probably do mostly battlegrounds in PvP since I no longer have active friends to play arenas with :( so sad... So, should I choose Icecrown server for my needs?

Second question: What class is in highest demand in PvE, especially in raids? I want to play mostly healer or dps in PvE, tanks are not my favourites but I can do it in dungeons I guess. The thing is, I want to choose a class that is the rarest. I dont want to be another Holy paladin for example, if theres tons of them. Back in the day when I played, resto shaman was probably the hardest healer to find, so right now im thinking either that, or a druid, or maaaaaybe a priest. So guys, tell me please, what do you think is the rarest PvE class out there that I should pick? My Priority is: Healing->DPS->Tanking

Thank you all, see you in-game. And... FOR THE HORDE!

[Thorbjorn]

Play on Icecrown, it suits your wishes best.

It isn't the rarest PvE class but take up Resto Sham. It'll be needed both in 10 and 25 man raids as a healer and RDPS so you're good on both fronts there.

[ImminentVictory]

thank you bro! Ready to hear more opinions if you guys have them! :)