Firstly, welcome to the Crons
Couple of key things to remember:
1) Don't let the troops get assaulted.
2) Several units need more than min numbers to be effective (wraiths, scarabs, tomb blades) spring to mind.
3) Don't let the troops get assaulted.
4) Don't let the troops get assaulted. :-D
Anyway, for your list, 3 wraiths is probably not enough. Also, whip coils are very helpful (not every wraith needs them, but you really want to strike first!). This is not helpful, cos you need to fork out for another box. If you only have three, I'd suggest you use them defensively rather than racing them up the field.
S&B lych are very resilient. Excellent protection for walking warriors, but otherwise need a veil of darkness or a scythe to get around.
In your list, you have two counter assault units (Lych and wraiths) but only 2 comparatively small troops. So, I suggest you drop one and add more warriors.
Keep a solid core of warriors/immortals, then try the units one at a time.
I don't play tomb blades, but imagine that 3 is also not enough.
Re your
HQs, Anrakyr offers situational benefits. It would be hilarious if you used him to take over a Heldrake, but generally there tend to be less vehicles. The Eternals upgrade is nice, but you don't want to be assaulting with only 5 eternals. I2 will kill you.
Tbh I think Zandrekh is better (even without Oby).
Re Res Orbs, only use them if you have models which are say 40pts or for max squads. For 10 warriors, probably not worth it - just take additional warriors for the points.