My main is a stamblade. There's no set "must have" range for stats, but there are guidelines.

Sets:

I like hunding because it's crafted, so you can make and swap pieces as you need (and it's still one of the best stam sets). My stamblade carries a full set of everything in hunding gold...so that he can always make sure to have five pieces regardless which secondary set I use. If you're bow/2h you have a couple of options.

1. You can go 5 hund, 3 agility, monster helm set...but this wastes the 11th slot. (However, the agility set compensates for this by design by offering the larger 2 piece buff).

2. You can go 5/4/monster helm with like a hunding/marksman setup or something like that. In this config, sometimes I use the weapon swaps to alternate the fifth trait, as in my 2h might be hunding but my bow might be marksman.

3. You can go 5/5/1 piece of monster. I have a hund/briarheart/molar Kena config that works well.

4. However, for a stamblade I really like dual wield, where I run 5/5/monster.

These are all viable. For pvp right now I love a bow gank/keep defense build with hunding and marksman, or for a melee assassin a hunding/viper build with either a monster set or 2 pieces agility.

Stats:

These are all on purple c150 food, which I always run. If it includes another buff I'll mention it. These stats are OUTSIDE cyrodiil. You get buffs in pvp, but it's easier to cite them outside for comparing. This is my hunding/briarheart/molar kena setup.

Crit: This is one of the least flexible since you'll get what bonuses your desired sets offer and your nighlade bonuses, then there's less you can do to adjust it. For a NB, I usually aim for 70%+. They depend on crit and burst dps. If my stats are low, the one thing I can adjust is putting camo hunter on my attack bar for a big boost to Crit. In my briar setup I actually hit 86.3%, which is important for that set. I get that with 3 assasin skills and camo hunter on my dual wield dagger bar.

Max health: I'm at 20.7k. Some people go lower for more power, but I prefer to be a little less squishy in pvp.

Max stam: 30.8. I've given up a little stam to keep some health and magic, per my play style.

Max magic: 15-17k. As a NB in pvp, I still require a fair bit of magic for buffs/sneak, so I don't want to let this get too low. I've done the all-out-stam build, and I felt like I couldn't pull cloak enough. So I use prismatic enchants on some of my gear. The bottom line with these is an all prismatic set gives up 1800 stam in exchange for 2400 health and 2200 magic. Prismatic on big pieces only gives up 1000 stam for 1800 health and 1600 mag. I am doing the bigs right now. (And I share monster helms across my vets, so prismatic makes them more flexible).

Stam recover: I have two pvp mundus strategies. If I'm under the shadow my recover is around 900. This requires getting in and completing the kill fast, or running away. And then I will supplement with siphoning attacks on my retreat bar, and good potions, and sometimes stam restore weapon enchants instead of poison. Sometimes I run the serpent and get like 1300 recovery.

Resistances: my current is 14k spell, 14k phys, 1k crit. He's squishy, but that's where they're at.

Weapon damage: This is where people do the most tinkering, and I can't say I'm an expert or that I go for the most damage. My basic dmg (on food, no ability buffs) is 3k. Then as a NB in pvp, I need major brutality, which brings me up to 3500. Get this from rally or hidden blade. You can also get it from power extraction. Rally is simply the best in pvp because it lasts longer and has an addl heal. My briars heart will raise my dmg to 4000 when everything is fully buffed. Then proceed molag, and I'm at 4800ish. And in pvp, I will run magelight on my back bar to get another 20% buff from might of the guild. (But mostly I use this in my bow setup, where marksman replaces briar and the opening sneak attack can hit for 15k).


Champion points:

You have a ways to go, and if some of my stats seem higher than yours it's probably from CPs. I've done a lot of CP tinkering, and here's what I've found. Most important, piling CPs in very useful things you use all the time is better than spreading them around. This is where I've focused:

Thief: 120 in lover, most in stam regen (90), some in health, a little in magic. Rest in tower, most in warlord with 10 in magician just because I do use cloak a lot.

Warrior: this one is not obvious, but when I reconfigured based on some better players' suggestions I found that the best points here are in hardy and elemental defender. I have 130 split evenly between them. This reduces all incoming damage, which I found to be far better than the medium armor line or anything else in red. I put a few into quick recovery, because I do heal myself a lot. And this is my pvp character so I have 30 in resistant. I use him for pvp and pve. In an ideal word, I'd recast him all the time depending on what I'm doing and really bump the resistant for pvp, but that's a pain.

Mage: ignore the atronach. Weapon expert skills sound appealing, but it's better to have power on every hit than to specialize in light/heavy attacks. I've poured most into mighty and precise based on expert recommendations, and this does really work. I also threw a few into blessed to bump my heals by 7%.

Note: you have a good pile of campion points, and you should be competitive. However, those next 300 will make you considerably more powerful. Don't get discouraged if you're a bit handicapped by not having 561. It's a long grind...it will probably take you several months...but slowly your character will get more powerful. Use your enlightenment and it'll slowly work up. If you want to focus on cp building, the new life festival is coming up soon (it's the same as the witches, but with stam rewards). You might consider grinding a second toon to 50 before then (a magic Templar?). During the festival, send your vets for the easy xp (dolmen clears, world bosses). You don't have to have multiple vets, but I found it easier to get to 561 by using multiple characters.

Other tips: it's a boring grind, but work up legerdemain to 16 so that you can reduce your sneak cost. This is vital for me in pvp. My grind strategy is to spend one skill point in the line that allows you to fence 220 items a day between sell and launder. I go to the inn in Orsinium and follow the path through the whole area...there are not many npcs and I pick up about 200 items in 5 minutes. I launder the cheap ingredient crap and sell the rest. It takes 10-15 rounds of this, but the sneak cost reduction is massively helpful in pvp. Fortunately, the first two points come quickly, then you can slowly work toward the other two. As an alternative, do the thieves guild pick pocketing dailies. This is more fun, and picking pockets works leger well too.

Hopefully that provides some guidance. Nightblade pvp pros are that they hit like a truck and are really fun to play. Cons are that they're squishy. But a stamblade has always been my favorite in pvp and I've never really liked anything else.