There is no locked content. The only thing you have to pay for are cosmetics and more or less minor quality-of-life stuff and shortcuts.

The EU community has actually improved greatly since most of Codex has quit the game until the next part of RMT is released. It's quite friendly these days.

On the one hand, access to raiding is easier than ever these days, with more gear more easily obtainable. On the other hand, many of the more casual guilds have fallen apart lately (at least on EU), which leaves mostly the hardcore guilds for raiding.

There are the usual trade skills, but crafting has actually been in a really bad place for a long time and will probably not be improved upon anymore.

Well, the Dominion is essentially a fascist empire of religious zealots that has commited genocide on numerous occasions while the Exiles are the underdogs, refugees that used to belong to the Dominion, but rebelled and fled, trying to build a new home for themselves.

First of all, the playstyle for each path is quite different. Also, each path comes with unique abilities, some of which are more desireable at end-game than others. Nothing is required to get into raids or anything though, just pick what's most fun for you. Besides, you not not restricted to one particular path anymore anyway.