Asking anyone in this thread how they feel about FFXIV is going to give you a skewed perspective - a lot of us have 4000+ hours in this game and no-lifed it at various (often low) points in our lives. And the other major 'pole' of the community (trannies, furries, streamers) is pretty much as anti-KF as you can get.
Here's the rundown of what you should probably know:
1) The game's main story line without any diversions will probably take you between 200-300 hours to complete. This is the baseline content of the game, and your progress through this controls the baseline of power your character has access to. It is often long and wordy but if you're a story fag, it does legitimately pay off so it's worth sticking through. If you're not a storyfag, you might hate it. It's important to progress it because the encounter treadmill it puts you on is designed to slowly teach you the mechanics of the game so you're not retarded at endgame. FFXIV has a generally consistent and well-defined mechanical language and not knowing it is almost akin to griefing. You can buy story skips that take you to the current xpac's starting point in the story. If you do this, I recommend getting a list of MSQ dungeons and fights and queuing through them to recreate the experience of organically experiencing them in a story run because, as I said, you'll be retarded otherwise.
2) The community is best described as conflict-avoidant. People will often go out of their way to help you but the rule of thumb is that if you're dealing with someone that is causing problems, just leave an instance and re-queue. There's a pretty heavy-handed policy towards verbal abuse and you can get smacked pretty hard by GMs if you go gamer mode on some casual. There's a built-in penalty system for leaving to incentivize you to stick around as well as bonuses for helping people get first-time clears, so balance that with the potential sanity loss of dealing with retards.
3) There's very few options in terms of character builds. Every character of a particular job will play almost identically to any other character of that job. Skill is mostly expressed by being able to play that job well. Slight tweaks to builds exist but they're astronomically tiny compared to just getting gear with bigger numbers and hitting your buttons correctly.
4) The community is extremely in love with the game's story and most people have sat through it. It's not like most MMOs - story is fundamental to most of the community's enjoyment of the game. Not being a storyfag makes you the weird one, so keep that in mind when dealing with other players.
5) Long-time players are inevitably jaded due to the pretty substantial gameplay changes that have happened over this game's lifespan. A lot of us are not particularly pleased with the long-term direction class and encounter design has taken and so we often have a doomer-like disposition when talking about the game. If you're having fun, don't take it too seriously.
6) All of the content creators are fags and SE rightly treats them like lepers. Ignore them unless you like watching tard drama.
7) High-end content is generally accessible - you can often find the base gear necessary to 'do' the content on the market for not too much money and there's a party-finding system that lets you build groups and work through specific pieces of content.
8.) Gear doesn't have a ton of long-term value other than for aesthetics. As a general rule, whenever a new raid tier comes out, the previous gear is all numerically obsoleted immediately by craftable gear. You can skip raid tiers during an expansion and jump back in with relatively little investment.