Hello. This newbie guide might help answer questions you might have about the game. However, I will be happy to answer your specific questions as well.
As far as community, it's pretty much always been very friendly. You have your trolls, of course, but you also have the ability to ignore them. And if you come across a gold digger, you can easily report them to help reduce the number in the game. You don't come across that many in this game, Trion has done a really good job on that part.
There is a Looking for Dungeon tool, which is available from level 15? The game tells you, based upon your soul choices and roles, which spots it thinks you can fill within the 5 group spots available in dungeons. You can either be a tank, healer, dps (2), or support. It's recommended that you have a role for either a healer or tank, because everyone can be a dps. That makes dps spots easy to fill, so queue times for dps are horrible. And support is usually just another word for dps, but sometimes the group will actually need a support. The guide I wrote explains more about roles and dungeon groups.
Zones, in the lower/mid levels, may feel a bit empty. However, when you come across a rift, especially a nightmare rift, it might feel a bit less empty. Don't worry, the game has recently updated to allow you to shift between shards at will (as long as you aren't fighting), so that you can hunt for more players, a certain mob, or whatever. And you can change shards once a week to permanently stay on a certain shard, for like if you find a guild that you want to join. It is highly recommended that you join a guild, there are passive and active benefits available to all guild members, especially if you are in a high level (25+) guild. The social aspect also helps, of course.
The game is always in flux. The developers do appear to actually listen to feedback from players, most of the time. This is unusual, because most games just decide what they want to do, players be damned, until things just go disastrously wrong. THEN they listen to the players... Trion makes mistakes, like any game does, but in general, the game is a blast to play. Of course, you get those who say it's dying, but don't listen to them. The game is very robust, especially when you reach the higher levels. And you can't make a wrong move, because unlike other games, respecs and roles aren't that difficult to change, and simply putting a point into something doesn't mean that you've screwed everything up and can't correct it. May cost you some plat, but hey, it's not that hard to remake it as you play.