That wouldn't be in my top ten choices, but OK.
Riven hourglass lets you reroll the occasional d20, which could let you make some saves. This is important because your class and archetype are pretty bad at recovering from failed saves and you're playing solo so no one else is likely to save you.
Handling social encounters boils down to having at least diplomacy, preferably a second social skill so you have options, and roleplaying in a way your GM thinks is good. A steelfist commando does not have options beyond this.
Vital skills are diplomacy (see above) and use magic device. You have to be able to talk to people, and to use wands and a few scrolls for healing yourself. Having stealth and a rank in disable device (to open simple locks) may be very handy but isn't essential. Anything else is nice to have at most.
I can't translate your last question, could you try rephrasing it?
At 8th level.
9 maneuvers known (7 1st, 2 2nd, 1 3rd) of which you have 6 readied. You're going to want a couple of the counters I guess (flowing creek and counter step?), and the 3rd level maneuver will be your big attack. Any of the 3rd level strikes could serve.
3 stances (2 1st, 1 3rd). If you're doing TWF then broken blade stance, if not then flowing water stance.
I've got to say while this character will be competent at doing damage in melee, they really want to be part of a team rather than a solo adventurer.
Steelfist commandos replace the warlord bonus feat at L1 with IUS and greater unarmed strike. You only get 2 other feats at L1 if you're human. Which you may be, you haven't said. Otherwise that looks fine.
If you lean into broken blade's combat maneuver options then underhanded trick might be worthwhile. If you decide you're good enough at combat already then umbral gear might be fun. Silencing strike could be handy for taking out guards.