Guild Wars 2

Hey guys!
Before you continue, I do own HoT, so I can play any spec.
I am a classical rpg player. I want a class to play 90% of my time in guild wars 2, maybe except pvp.
I currently have a thief I enjoy rather much. My concerns are mostly about not being taken in public raids, or high fractals.
Furthermore I tried a bit wvw roaming…and failed miserably. To be viable seems to take a high learning curve. Also being so squishy feels not very good, but maybe I am just too bad for dodging at the right time.

I also have an elementalist, I like those 20 skills, but sometimes I feel a lack of bursting in pve, if I watch at my thief, and that I feel squishier than a snowball in hell. A bit wvw was devastating for me, and destroyed much of my fun with the class.
Some of my friends told me the dps rotation in raids is similar to playing a piano, which means a skyscraper high learning curve (but I am not sure here).

Thirdly I created a guardian. I like those high numbers, I am not so squishy and can do most things by myself, but especially in wvw I feel very slow and cannot catch any other player. Most of the high damage of guardian is based on aegis uptime, which is literally not existant for me.
The necessary rune of the traveler for wvw also scares me away.

What would be your advise?
My priorities are (highest to lowest):

• (high) fractals
• wvw (solo)roaming
• raids (and contributing something to the group)
• wvw zerging
• pvp

Many told me I can play literally anything in Open World, so there should be no problem I guess.
I hope I get some answers…or maybe GW2 is not the right game for me, it does not feels like having a main, and rather having a class for each playmode.