The inn, in my opinion, is a must have for all my characters for a long time. There are far too many useful items you get as quest rewards that I couldn't live without after having them, avianna's feather being a prime example. Flying in draenor? Yes please. You can also headhunt scavenger followers and build a set of them to counter each mission type to handle your resource needs.
Lumber Mill is completely, 100% useless. The only reasons you'd ever get it is if you want the phylarch follower (and bulldoze the mill after you get him) or if you want the treeassassin disguise to drop combat in draenor which is pointless for some classes and not all that great for others. I dont think ive ever been in a situation in WOD where i was in danger of dying from random trash mobs out in the world. Lumber Mill's primary purpose for existing is the generation of resources at garbage quantities. 20 per 4 hours, or 30 per 4 hours if at level 3 w/ phylarch assigned. With scavenger followers running resource missions, you will generate way more resources than you can possibly spend no matter what you do and it makes the mill obsolete.
Inn is the better choice, and one of my required buildings until such time that i'm "done" collecting new followers (for whatever reason) and that I have all the useful/fun items.
The alchemy building makes sense, assuming you're an alchemist and want the extra daily cooldown materials to make the best flasks.
Inscription building is kind of useless at this point. You can't make darkmoon cards with it, unless you're also a scribe and use it for the extra war paints. Then you can, but (at least on my server) darkmoon card prices have dropped significantly. they're going for less than 1k per card now. The trinkets still sell for about 20k, but that'll wear off as soon as all the stupid people realize you can buy the cards for the deck with only about 8k. Jewelcrafting building and jewelcrafting profession combo are going to be much better for making money long term. Those greater taladite gems are going to sell like hotcakes for the entire expansion. The opportunity to milk inscirption for gold has passed, all that profit to get the trinkets right away is kinda gone. The price of those things will only drop at this point.
JC and Alch will both remain profitable in the long term.
Enchanting building is a solid choice though if you don't have a chanter since you can simply dust your unwanted items and sell that for money. Keep in mind though, BOE items should be sent to an actual enchanter and not use the building because real enchanters get more mats per disenchant.
Also if money is your thing, you should get a barn. You can get the best feasts as well as savage blood, both of which will sell.
Another nice thing about JC + Alch is your mine can feed your JC building's workorders and the herb garden feed the alch one. Alch + Inscription would tax the garden too much and you'd need additional source of extra herbs to keep both running efficiently.
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Bunker's primary purpose is the free seal of tempered fate each week. Once you start shelling out gold, resources, or apex crystals for them every week, you'll quickly realize having one of them being free is a godsend.
Also gears up followers very quickly, which you may or may not care about, but fully geared followers can run raids and bring you epic loot to use, so that is always something to consider. If you just drop a couple work orders in there on occasion, you won't get much out of it, but if you keep those workorders maxed all the time (which you can easily do at no cost with a bunch of scavenger followers) you'll start to see lots of follower upgrades.
There's also the transmog to consider if you care about such things.