If you played through (or through most of) Heavensward, then it isn't very hard to get caught up. The MSQ between HW and SB isn't nearly as bad as ARR to HW and a far better story.
I never played EQ2, so I really can't compare the two systems. However, I am extremely familiar with FFXIV housing, so I can at least comment on that. I'll toss up some pictures of my house in a bit.
Housing is non-instanced, with the exception of apartments. You can buy a house as a personal house or as a free company (guild) house. You are limited to one of each per account, although if you are in a guild, you can't buy a guild house if you aren't the guild leader/your guild isnt a high enough level. There are small, medium, and large sized plots and houses and currently 4 different housing districts (Goblet: A Desert Canyon spot, Mist: Beach/Mediterranean style, Lavender Beds: Forest based, and Shirogane: Japanese style housing). You can customize the appearance of your house. Some appearances are locked to the zone (ie, a Goblet style house appearance cannot be used in Mist), but there are also universal housing skins that work on any house. However, you don't actually "build" your house in a mine-craft sense so the outer model is just going to conform to the skin/appearances you are using. The way the game is setup, you cannot directly sell housing to players, so this has kept the gold bots away (unlike Archeage where they grab land for the purposes of reselling). Once you buy a house, it is yours so long as you enter your house once every 45 days, so there are no taxes. After 45 days, I believe you get a house demolition warning and the house eventually poofs, allowing others to buy the plot (your poofed house+items appear on a NPC and stay there for 30 days so you can get most of your gil back and your housing furniture).
If you have an actual non-instanced house, you can decorate your yard (10/20/30 items based on land plot size). If you buy a mini-atheyrite (from the grand companies), you can teleport directly to your house. There are a variety of outdoor only items you can use and you can even have your retainers appear on your property (they act as stores if you put items on them for sale, so in theory people can buy directly from them vs. the marketboard). You can also garden outside, which is used to get some valuable items for crafting (mostly through crossbreeding plants). The number of garden plots are limited by plot size (1/2/3). You can also stable chocobos if you build a stall, which is mostly used if you want to breed chocos for racing at the Golden Saucer casino or level them as a combat pet.
Inside the house you have an item budget of 200/300/400 items based on land plot size. Small house is 2 floors, medium and large are 3 floors. Besides furniture, you can customize the ceiling lighting, floors, and walls on a per-floor basis. Where you can place certain items in the house may be restricted unless you use glitches. SquareEnix doesn't fix the glitches because they have publicly supported what players do with them. The only glitch they fixed was an Aquarium clipping through another Aquarium one that caused game issues and also "void zone building" glitch which let you place furniture in a black void outside the house with no limits, which caused some strain on the game. Using glitches you can float certain items or place items on "illegal" surfaces that the normal game placement will not let you. Most of the nice looking houses at the housingsnap website below use these glitches (my house does as well)
If you want to get into housing, I would strongly recommend you level crafters. Even semi-low level crafters can make a surprising variety of items. Making furniture is a shitload cheaper than buying it. Retainers on missions can bring back furniture, though, including expensive items. A lot of the HW housing items have also crashed in prices. I used to be able to sell a moogle shaped shrub for 1.5mil last year, now it is 15,000 lol.
For additional info:
FFXIV Housing = This site contains a database of all the current housing furniture items and where they come from
FF14ハウジングSS投稿・共有サイト = Japanese site with images of houses people have made to give you a better idea of what you can do ingame