Good luck ive had some great games with TK they are a challenging army to play with. My first piece of advice would be to go and submit your list on the forum TombKings.net there is some really good players over there and if you can endure the occasional Nerd rants you will learn alot from this forum.
here is the link
http://z4.invisionfree.com/Khemri/index ... 4a&act=idx
Hopefully i will see you over there my username is RustyGates1989
on your original questions.
You want 6 NK in a unit i find that they last longer, don't seperate your skeleton warriors, you want to use them as a tarpit put 50 of them in a unit with sword and board. No Spears you dont want to be hoarding these guys and the spear is not worth the points as Necro said a prince in this unit will make these skeles ws5 wich can be areal pain for opposing core. If you are going to take NK Take Ramotep he gives a random construct unit re-rollable saves. if you are planning on taking NK as your only constructs then this is a given. 3+ rerollable for win
On the TG horde, give them the halberds and the Razor banner. You need this as this is one of TK only answer to the growing meta of Monstrous cav. I would recomend the light over death but thats preference. Wow im starting a rant.
Best advice go spend and hour or 2 reading on the forum, post your list and listen to the feedback, Vallah, Jimmy and Krael are all really experienced players and any advice they have in threads is worth listening 2.
Sorry for Rant