Theres some debate about whether you need hasten for MA but personaly i've never needed it with 1 recharge in each attack power.
Placate at 12
i7 isn't here yet so planning to 50 is pointless.
Tough out of the box for stalkers is 7.5% res ..not really worth it.
Defiant's GoEH/MILITIS METUS
I'd have storm Kick and Crippling Axe kick as my first two attacks personally
"Well, they found my diary today.
They were appropriately appalled
at the discovery of the eight victims
They're now putting it all together.
Women wrapped in silk
with one leg missing
Eight legs, one body, silk,
spider, brilliant!"
I have just such a MA/Nin stalker and I'd second that last post - crippling Axe kick is really quite powerful and if you plan on scrapping a bit then I think you'll like it.
I'm currently lvl 22 and made almost the same choices as you except I choose Cobra Strike for its disorienting effect which I like when scrapping - i.e. if you're fighting two people it stops you getting hit by one and ruining your AS after you placate another (BU, AS foe1, CAK foe2, Cobra foe2, Placate foe3, AS foe3, CAK/SK foe2 till dead) but i'm ALWAYS running low on stamina and now regret leaving it so late (I won't have it till 26 unless I respec). So you might want to think about Cobra Strike later on but get stamina asap.
I also took stealth for PVP though to be honest I haven't done much with it - BB always seems empty 
so I could have left this till later I think.
I took Jump Kick instead of Combat jumping to get an extra attack - regret!! Just adds to the eating of my endurance and isn't very good (though maybe if I put more enhancements in it it would mak a difference).
And finally I didn't take Hasten - but this is just a personal choice based on a lack of knowledge lol 
Superjumps great for hit'n'run which you'll often need to do when soloing.
All in all I love my stalker.. but look forward to a respec 
I'd get Placate earlier, next to AS it's your best friend in pve or pvp.
The Smoking Demon
Ash/Tar Corruptor
Union
@The Smoking Demon
[ QUOTE ]
I'd get Placate earlier, next to AS it's your best friend in pve or pvp.
[/ QUOTE ]
Doh, with travel powers included you can't get it any earlier I think. How easy I forget hiding behind trash can's and cardboard boxes till lvl 16.
The Smoking Demon
Ash/Tar Corruptor
Union
@The Smoking Demon
I'm playing with my first Stalker, and I'd like to make a MA/Nin. I know there are two ways of play/design a Stalker: a hide/hit/run one or one that has AS only as alpha attack, but that plays as a scrapper. I'd like to make the second one. I need some help with the powers, I haven't find a MA/Nin guide, so please fell free to suggest changes in the order or even the ones I've chosen.
1. Thunder Kick
1. Hide
2. Storm Kick
4. Ninja Reflexes
6. Assassin Strike
8. Combat Jumping
10. Focus Chi
12. Danger Sense
14. Super Jump
16. Placate
18. Hasten
20. Hurdle
22. Health
24. Stamina
26. Kuji-In Rin
28. Dragon's Tail
30. Kuji-In Sha
32. Acrobatics
35. Boxing
38. Eagle's Claw
41. Kuji-In Retsu
44. Tough
47. Conserve Power
49. Cobra Strike?