It never was mandatory to level all the jobs, and it still isnt. It is advisable to level them all at least a little ways for cross class skills, and the people who get into crafting tend over time to level them all(or at least most) up for the advantages it offers. So lets start with cross class skills. The most recent patch removed 2 highly sought after CC skills from crafters, and made the skills native to all crafting classes instead. So any guide telling you to level Culinarian for Steady Hands 2 or Carpenter for Byregots Blessing is a little out of date - you automatically get these now. In general, the advice to take every class to 15 for the first set of CC skills is still good, and several classes still get great CC skills at 50 or later(all but arguably carpenter and leatherworker).

Beyond skills though, the real benefit to having most/all classes leveled is the freedom to make your own mats. Lets look at one of the most recently added glamour items, as you said glamour was of interest to you. Lets examine the Hooded Fireglass Leather Vest. Its a sharp looking top, you might want to wear it(or sell it for millions). So how do you make it? Well, its a leatherworker recipe, so first you level that up to 80(its in the master recipe book volume 7, so also earn 1200 red scrips and buy that book). Then you need to get or buy the rare mat, in this case Fireglass Leather. This mat, like several others used only for glamour recipes, comes from treasure maps. You need 3 for the vest, so you run some maps or break down and buy off the market board. The hard part is done, what next? The vest uses some weaver materials(2 pixie floss and 1 pixie cotton - maybe to sew the leather pieces together) and a goldsmith material(a stonegold nugget - maybe for the ornamentation on the vest). Those are low 70s materials for WVR and GSM, if you have them leveled you can make them yourself to finish the vest - if not, you need to pay the market rate for them(which is ridiculously high for some intermediate to high mats). So this one leatherworker piece also used three weaver or goldsmith items. You see this in almost all of the higher level recipes, needing items from several classes to finish a craft.

So back to your question: if your goal is primarily glamour and furniture, your initial list of classes looks good. The crafters and gatherers you picked will do the majority of the glamour and furnitry work(and BTN/MIN will get the majority of the mats for said work). That said, ALC has the furniture "plant" items and CUL has some "food" furniture items as Nanami mentioned. And BSM+ARM both have furniture and glamour of their own to offer. They also both had really useful high level CC skills(Ingenuity 2 from BSM is still a keeper, the recent changes make me unsure how much i recommend Piece by Piece from ARM - i need to study this more). Keep in mind, for leveling crafters you have 3 beast tribes, leve quests, GC turn ins, custom deliveries, crystarium deliveries, and collectables in addition to just making stuff. Leveling a class for later use doesnt have to mean anything more then turning in an item here and there when its cheap and convenient to do so.