1. There are areas that are inhabited by different mob factions or types. Most areas are fairly accessible (once you get into the 56+ range and move into the Valencia desert area you lose your map and can contract hyper/hypothermia during day night cycles). Profitability depends on area and mob type/drops/etc. Combat is pretty fast, can be trivial especially depending on class and what mobs you're hunting, but can also be challenging if you aren't good/geared etc. I still really enjoy the game after playing since official launch. PVP adds a large fun factor to the game and you would be doing yourself a disservice if you completely leave it out. Larger scale PVP in general is more fun than random ganking, but to each their own.
2. PVE game is lacking in the traditional sense. You have very little group required content, with most of it being limited to summoned encounters from scrolls you can acquire daily/weekly/randomdrop. Raiding is limited to variable timer spawned world bosses that giant zergs for the most part. You don't have dungeons in the more modern style, but there are definite areas that have underground/ruins/cave/fortress sections that you can camp or crawl through. Named mobs don't really exist outside of world bosses or scroll summons, loot is most random, with different mob groups having loot tables they pull from. Grind is real. Once you get into your 50's, especially 55 and up, xp slows way down, and progressing through levels and combat skill ups can get tedious for some. All this being said, I enjoy the PVE aspects of the game. It has the loose, do what you want grind of old EQ days, with some camps for popular xp areas, and to grind certain drops. I like combat from the character perspective and I think this is one of the shining features of the game. It is probably the best action style combat I've experienced in an MMO setting, most classes (haven't played them all) have a wonderful flow to their combat style, which makes mowing down endless waves of mobs enjoyable to me YMMV.
3. The gear grind is my biggest issue with the game. It is a grind that is facilitated by RNG smashing items together, hoping they combine to upgrade. Weapons and armor don't completely suffer from this, but accessories break on failure, leaving you with a lot of wasted silver and angst. Weapons and armor degrade their durability on failure and can be repaired with like items for continued attempts, but once you get into +16 and up, failure can result in downgrading, an example being going from +17 back to +16. Some prefer to just money grind and buy their gear, which is my current and preferred method of madness. Money is easy to make in the game from grinding, tradeskilling, fishing, literally whatever floats your boat. That can be a negative for some people as well. This game has damn near an endless list of things to do, and that has been overwhelming to some of my friends that have played. Lastly, combat from the mob AI side of things is also very lackluster. Most encounters consist of corralling packs together, and AOE'ing them down while dodging/blocking/evading their attacks, which takes some wonderfully constructed abilities and skill sets and reduces them to the same tired rotations for most classes. PVP, and it's by default varied nature, is where knowing your class makes combat shine. The PVE just doesn't provide enough variation in strategies to challenge or force most classes to their fullest potential.
Overall, it is a great game, with some flaws. My best recommendations are to find a class you enjoy, get a decent guild that fits your playstyle and will allow you to experience some of the better PVP aspects of the game, and just have fun however that translates to you in this game. It is a great sandbox ride, with a great class/skill/action combat setup, PVE that I wish was way more fleshed out, and some really great PVP. I specifically am not going to go into Cash Shop, P2W, etc because it's been covered in this thread already, and to me has no real standing on the game unless you want to be top 1% bleeding edge internet champion epeen wanker blah blah blah.