My issue is that leveling is simply way too fast and that small group content is not there. Too much of the content outside of experts and dungeons are soloable with almost no challenge.
This seems unintentionally misleading -
The leveling does not stop at level 50 - it actually just starts. For PvE you'll need to repeat dungeons many times to gear up (increasing Hit or Focus for DPS, along with other stats to make the cut for content) - you will also need to grind faction points (repeating low level dungeons in fast 15 minute runs, or running around a circle with a large group in one of the zones killing all the mobs).
Raid content has obvious and not so obvious requirements - 200-300 hit/focus for DPS, along with 900+ DPS for Ranged and 1200+ DPS for melee for raiding. Similar requirements exist for healers and tanks - all based on specific bosses. Beyond just learning the mechanics, the raid needs to pass Tanking / DPS and Healing checks during progression.
There is some limited 10-player content, but most of the end-game raiding requires 20 people, and that usually requires a guild with 30+ competent members willing to raid at least 2-3 times a week.
The good - when your skill/gear level increases the raids become increasingly faster - what used to take an entire 4 hour evening to clear can later be done in 1-2 hours. Trion also made some of the entry level content easier - and with following good guides you can catch up to other players.
For PvP it's even more complicated - you start as cannon fodder, dealing up to 30-50% less damage to opponents, and having no access to some useful PvP-Only skills.
Valor - the PvP-only stat - reduces damage taken from everything, and stacks with damage resistances you can get from your PvP-only tree that's Prestige-Rank based.
What you need is to earn Prestige, which you get for assisting on kills, and completing PvP related quests (which may be difficult with the open-world ones). Most of it you'll be getting from Warfront grind - and this depends entirely on your server choice. On some servers one of the sides is just better and has faster queues then on others - leading to faster progression and in increasing advantage.
What is worse, just doing PvP won't be enough - you'll also need to raid to get the best Weapons - the gear you get from PvP doesn't have some of the key stats for PvE making it difficult. You'll need to spend time doing both to stay competitive.
In terms of overall time investment - you're going to spend at least two-three times more effort on the hidden leveling after 50 then you did reaching that levels. Expect hundreds of hours dedicated to catching up - and applying to an active ~25+ member guild to enjoy most of the content.
Looks for some DPS build suggestions for my mage. My main spec is a necro / lock but I'm struggling to turn out the DPS. Perhaps its my rotation. I've been recently trying out a Stormcaller / Elementalist build. Still working out the kinks with the built. Certainly seem to have a lot of AOE damage with this build. What is a good build for single target nuking like on a boss fight? I'll have to update my post with my build links when I get home. I don't have access to it at work.
Look for guilds that achieve world/server firsts and see if they post any guides or participate in discussions. Only take advice from someone with proven reputation, as it's easy to get derailed and run sub-par specs in Rift. Be careful - guides can become updated and misleading after a patch - big patches like the recent 1.3, or even smaller fixes/updates. Try to find the latest opinions.