I have a Breton magblade. He was a vampire for a while too. I liked vampire, but I found him too squishy, although vamp magblades are very doable. He was my...hmm...fourth vet, I think. A Breton magblade is fast as heck, a permanent sneak thief, and fun to play.

1. Check out syphers magic nb builds. No one is doing updates because the meta hasn't really shifted significantly. New builds are mostly Imperial City builds with maybe a different set or a skill or two changed out.

2. You'll level dual wield by having those weapons equipped even without any dw skills. However, the more skills on the bar the faster it levels. I like to round out skill line or ability leveling by creating a "turn in bar" when I grind. Go close dolmens and clear dungeons. Use your active bar to fight, then switch to the level bar for the big xp rewards (i.e., closing the last dark anchor chain).

3. Leveling all skill lines: you can do this on a single character. My main is 50 down the list. However, I find it more efficient to stick to stam lines for stam toons and magic for magic. In other words, I don't level destro on my other steam characters, and I don't usually level all the weapons on magic toons. For a magblade, the staffs are essential, dual is great, bow is pretty good and I only do sword and board or two handed if I really want a specific skill.

But for a "mega character," a really versatile one like you're describing, you can definitely level most of the class skills and a lot of weapon skills. Just make it a rule that you always keep 2-3 unleveled skills on your fight bar, and use a leveling bar with all unleveled skills for big turn ins. I even unmorph my skills often to try other variants. The game "remembers" where you left off on a morph level...you can level both morphs to lvl 4.

For the main lines...not the skills, but the weapons, a magblade can have an attack bar with no weapon skills...all class/mate guild. Just use training weapons with this bar and that weapon line will go to fifty quickly.

4. Morphs: how long a morph takes to max level varies...a lot. Some morphs will max out in an afternoon...barrier (support) takes a month sitting on your active bar...I think it's the slowest.

You can respec whenever you like...it's only like 1500 to undo morphs. But like you said, no need to respec for every skill. I usually respec once I have three or more skills I want to change up, or if I want some quick skill points. With a magblade, the good news is that on half the skills you'll only want one morph. No need to level up the stamina versions, like you'll only want to level lotus fan, not ambush. Then another quarter of the skills have one sucky morph...no need to level those (it will be intuitive when you encounter one - one morph is like "creates a damage shield for 6000" and the other is "frost astronauts laugh at you.") So that leaves about a quarter of the skills where you might want to level both sides of the morph.

5. Mage: skill line levels by collecting blue books, skills themselves work exactly like other active skills...put them on the bar and they level.

6. Vampire: skill line ONLY levels by having vamp skills on the bar. Skills themselves work like any others. To level vamp fast, go grind public dungeons on psijic with three vamp skills on the bar and two fighting skills you use to plow through enemies. Don't pay crowns for vamp...look in the vamp bite thread or just post zone text chats politely asking during busy times. People are totally willing to help, usually for free.

If you're a brand new player, wait a bit before vamping him. (You can contract vampirism any time, just wait to activate it). One, without champion points you'll need to be at least level 20-25 to survive the vampire initiation quest. But two, vampirism makes you a bit squishier. If you wait until you're leveled a bit and have your skills up, it'll be easier to adapt. Maybe like level forty. But if you're excited to vamp out, you can do it earlier.

Also, there's a crafted set specifically for vampires. You can look it up on the craft set list, it's vampires kiss or something. It helps provide health back and is really useful for a non-vet vamp. Use zone chat and ask someone to make it for you when you need it.

7. Don't forget the armor skills for a magblade. Shuffle (medium armor) is great, gives a 20% evasion with some perks...although I forget how this compares to mirage/double take and which is superior. the light armor skill is also nice...a damage shield that returns magic when you're hit.

Other general tips:

Maybe Start researching armor traits now. There's an iOS / android app called workbench that can help track this. Maybe you don't want to be a crafter or spend too many skill points here, but you'll be way more self sufficient down the line if you can make at least six trait armor sets.

It's boring, but steal and fence your limit to grind legerdemain to 16. A magblade NEEDS to spend all four points reducing the cost of sneak...totally essential. Here's my grind on toons. By default you can sell 50 and launder 50'items per day. I spend one point in the passive to increase this to 110/110. I go to the inn in orsinium and there's a path all the way through several rooms with very few npcs. In about five minutes, I can steal 200ish items with no bounty. It'll take about a dozen times doing this to get the line leveled. (But higher legerdemain gives you better items in chests and drops).

If you have access to thieves guild or dark brotherhood, magblades are great at the dailies you can pick up on the hideouts. Both require you complete the second quest in those storylines, then they open. They're called heists and darkmsacrements, I think. They reward pretty valuable motifs. My friend has two magblades and runs those on both daily, and he sells like $120k a week in motifs from it in guild stores.

Hope that helps.