I want to play tank mainly but also 2handed DPS as DK. So I wanted to level both sword and greatsword as I go up, and get some tanking abilities and some DPS abilities, like not completely specialize in tank to start. But I dont want to screw myself and not be able to get all the good tanking tanking skills at the end.

Is it possible to cap out every tree and skill? like even including the fighters guild, crafting trees etc.

No. It's been comfirmed there will be just under the amount of skill points (AT THE MOMENT, even if you collect every skyshard) to max all skills when launch comes.

For what you want, 2h and 1h+shield trees, + class + some crafting + armor passives there will be enough as you level, as long as you hunt down all skyshards in an area before leaving. Just remember just because a skill can be unlocked in a skill tree, doesn't mean you MUST unlock it, read what it does and see if its helpful to your play style, you don't need all 5 actives from any skill line.

Honestly, you can probably work with just the sword+shield line for both tanking and DPSing (especially since the former involves a lot of the latter anyway), given the number of skills that aren't weapon-specific in the class/guild/etc lines.

What do you mean by just under, like I dont care about using skill points on Staff's, Bow, and a few of the crafting skills. So will easily end up with enough to cap everything in all these: 1H Shield, 2H, Dual Weild, all 3 Class trees, all 3 Armor trees, all 3 Guild trees, all 3 Alliance War trees, 2of3 of the World trees, Racial, and 2-3 crafts ?

I'm sure you can max all those, but whether you can do it "easily" depends on your definition of "easy"

There are a lot of skill points to be had, but you have to do challenging questlines and go skyshard-hunting in dangerous locations (including Cyrodiil) to get em all.

I'd pick one role first, probably DPS, and get it to a comfortable level. Then add in the other. You can't max out EVERY skill, but you can max out a lot of skillsets by the time you've seen and done everything.

Fair enough but i really want my first character to have maxed out Tank stats, but I do want to start as DPS low level a bit. Just again verifying that by doing that I wont screw myself out of maxxing tank skills later?

Also is there anything about a way to reset skills and respec character?