4 / race
Edit: Woops, there are other passives too, not only the racial ones.. There are loads of passives; weapon passives, racials, guild, alliance war etc. etc.
Check this out: http://www.esohead.com/calculator/skills
As many as you have skill points for if you are willing to level the skill lines far enough.
Yes, you can have as many passives as are compatible, ie you cant use dual wield passives with one hand and shield.
Yes, you can change your skills at any time provided you have spent skill points on your desired skills.
No, you do not have to use an ultimate; just as you don't have to actually use your basic skills. However, and what I actually believe you meant by your question, you can not swap out your ultimate for an additional basic skill.
You have 5 active skills + the ultimate, which is also an active skill. You switch weapons and you have the same (all assuming you've actually spent skill points in these active skills). You can spend all your skill points in passive skills if you like.
Do you know the difference between passive and active skills?
Yes.. yes, yes, yes and yes to everything
That's actually what I'm looking to do aswell with my archer (unless melee in first person is changed to feel more effectful, then I'll go tanky-spanky).
Your passives are always there, but they don't always apply.. for example if you look at the Bow passive skill Long Shots, it will not apply to you directly when you're in melee using DW, but if you move out of range from using melee hits then Long Shots should actually be activated (granted you move far enough away from the target). Now you can ask yourself how useful Long Shots are when using DW, Hidden Blade (Dual Wield active skill) should take into account the extra bonus from Long Shots, for example, but not for Twin Slashes (another active skill in the DW-tree)
What about passive: eaten food have twice long acting time. Do I have it to be selected while I'm eating? And then the buffs are kept longer even if I change it to more usefull? Or I just do not have to select it?
For those Passive skills with multiple ranks, such as the Keen Eye skills for the Crafting professions, can a player immediately dump multiple points into them, provided they meet the level requirements?
For example, the Alchemy Keen Eye passive skill has three ranks beginning at Alchemy level 2. Let's say I am at Alchemy level 2 (so I meet the level requirement) and I have three skill points I want to use immediately on all three ranks of Keen Eye. Do I need to wait between using the first skill point for the first rank and using the second skill point for the second rank? Or can I apply all three skill points consecutively without waiting to level up my character or waiting for the skill to level? Is there a usage requirement or leveling curve for the Passive skills?
I never reached a point in my Beta sessions where I had more than one unused skill point at a time so it seems unlikely I will ever encounter the above scenario one the game goes live. I know the Active skills have ranks that require the player to use them before the next rank can be reached; but I did not know if Passive skills behaved the same way.
@Lone, the passives are leveled tiered, so after you put that 1st point into Alchemy Keen Eye, you can not put the next point in until alchemy reaches level 10 (for example..that's not the exact level)
Just look at http://www.esohead.com/calculator/skills and figure it out on your own really. It comes down to what your preferences and what you are ready to give up in order to have those preferences but still being good enough performance-wise
But from the top of my head I'd say Nightblade.. but from my own experience Bows don't really have the same DPS stance as in other games, it seems like Bows are mainly used for PvP or solo PvE. There's no synergy for bows and the skills except from Siphoning and while Siphoning is good for solo PvE it's actually a lot worse than for example a DK (Ardent Flame) in terms of DPS in a grouped PvE enviornment.
Passives work like this.
You can buy them all with skill points and by leveling up the skill lines. now the character will not have them all working at the same time because they are linked to items and equipment such as the dual wield 15% exp for the dunmer. That racial passive will only work if I use two one handed weapons. The heavy armour skill resolve will only work if I am wearing one or more pieces of heavy armour, but will only get better results if I am wearing a full set. So if I wear only the helmet of heavy armour I only get a 1% increase to the stats but if I wore all 6 pieces of heavy armour those stats go up to 6%.
So a passive will only become "active" on your character if you use the correct equipment or items. You may find some nice synergies with them if you look and we learn more about the game though.