One thing you'll have to do is reach high level and very hostile areas to craft set items. Because of that you really shouldn't do it on a crafting only character. You really need a 40ish or high. One thing you can do is level a normal char, then respec all points into crafting.

If you want to be able to get every perk in every craft, you need 129 skill points.
This means that you never have to go over level 50.

You get 49 skill points up to level 50, then 16 dungeons, around 100 skyshards (depending on which faction you go with) and that makes 155 skill points. There are also 6 mission skill points in each region (making 36, not including cold harbour).That means you have 62 skill points to use for combat. We shall call them Combat Points (CP).

So, which class should you go with? I would say any class is easy up to level 50, but Dragon Knight is probably the easiest (or noob friendly).

In terms of class, I would say Orc for brawny and robust (so you don't die easily). So that will cover 6 of your 62 CPs, leaving you with 56.

You will want to take the first skill in each class tree, to level them all up evenly. Down to 53 CPs and then 50 once you morph them.
Recommend stone fist to stone giant, spiked armour to razor armour and fiery grip to empowering chains.
You want to head towards the magma armour morph of corrosive armour for the ultimate (basically invincibility), leaving you with 48 CPs.

For weapon, it's really up to you, but I would probably take one hand and shield so you don't die so much. Only problem with that is you have to take most of the passives. Take the first ability for levelling purposes and morph it into ransack. This also allows you to play a tank for dungeons. This leaves you at 46 CPs but down to 36 after all of the passives.

You want to eventually get dragons blood and morph it into green dragons blood (instant heal and stamina regen for blocking). So we now have 34 CPs.

You want to max out draconic power and earthen heart passives for more survivability (DP) and ultimate gain (EH), leaving you with 18 CPs. You also want all heavy armour passives except juggernaut (you wont need the 7% extra damage), putting you on 9 CPs.

This completes your ability bar and you shouldn't have to change it much at all to get all the way to level 50. If you find yourself in trouble, just get some mates or guildies to help you out.

You can use the remaining 9 CPs to get more abilities or sink them into more passives, it's really up to you.

Just on a side note, I play a really kick ass nightblade, so if you would rather play a NB than a DK, let me know and I will guide you even better.

Easiest way?
Level up a character as normal. While also doing some crafting on the side (so you do not have to start from scratch and maybe got some reserach done). Then totally respecc for Crafing.
You will need tons of time to unlock all the traits anyway.

The main issues right now is inventory capacity. So get a Draft Horse and feed it oats till it is full (+60 Inventory)
Even then doing all crafts on that one char might be impossible/infeasible. I currently have a Main crafter (wood+black+cloth), one Encanting & Alchemy crafter and a Provision mule.
With the extra inventory from horses they are barely useable for PvE content (not enough loot room/no alternative gear).
One for all might just be impossible with current inventory restrictions.

Advisable Addons:
Crafting Material Level Display
Multi Craft Addons
AI research Grid (gives overview wich Character can do wich trait)
Sous Chef
Something that stores data about alt's inventories (Vicsters Inventory Insight)
Something that allows semi-automatic transfer of materials between alt's via the bank (Personal Assistant).

I have a few characters that do crafting as it wasn't feasible to all crafts on a single alt and I have buddy characters that swap crafted goods. When I reached max on smith I deleted the other smith alt etc.

Inventory space is the real killer for me. I have even considered the imperial upgrade to get cheap horses for the bag alts.

I have a crafting alt. She's an Imperial, and I leave her logged out near the Night's Silence crafting station.

She's level 38, but she doesn't even need to be that high level. She still has a load of skill points left over, and she has Provisioning, Woodworking, Blacksmithing and Clothing all at level 50.

What I did was this; each time I'd return to town with my main, I'd dump all my weapons and armour in the bank, log onto my crafting alt, then deconstruct them all straight out of the bank, without even leaving the spot.

Then each time my main would hit a landmark, I'd simply log onto my crafting alt and craft him some gear. You can either bank the gear and grab it that way, or mail it to a friend who can 'return to sender', seeing as you can't mail yourself.

If I had to give you some pointers, it would be to train Keen Eye on your non-crafting character, at least for alchemy, since plants are sometimes hard to spot at night.

Another point would be to fill your bank with weapons an armour before you log off each night, then wait until the following day to deconstruct them. The reason being is this; you're able to check to see if you need to research any of them before you deconstruct anything.

Good-luck. Oh, and get a friend to teleport to the Coldharbour Wayshrines, so that you can teleport to them incase you need those 8 trait stations (you'll need to be at least V1 in order to access the Craglorn ones)

Edit; Oh, and if you can roll Imperial then go with that, since the Motif for the Imperial style is extremely rare and expensive. You'd be better off just being able to craft it from the start.

All I did was run a character to V1 then respec and used his skills in all the crafting tabs. At V1 you should have well over enough to fill out everything.