Well, the Wardancer, without question, is necessary for making this team competitive in the starting game. He's probably going to be the fastest player on the field (unless you play a skaven team or something), and he's really hard to knock down. He should be your main player for the first game or two.
The line-elves (calling them line-MEN is a sure-fire way to utterly convince them that they cannot dodge very well, so they won't) are neccessary because they are the cheapest players available to you, and you have to start with 11 players. Don't worry though, they cost 70K each for a reason, namely that they are the best athletic linemen in the game. They can keep up with or outrun most other teams' speedsters, especially early on, and the fact that they all have AG4 means several things.
I choose to start with 2 RR's because that is the maximum number I can have while still having a Wardancer on my team, which I feel is essential, and having a good FF, which I also feel is essential. (I'm getting to that part.) I'd love to start with more Re-Rolls if I could (I sometimes start undead teams with 6), but I just have to sacrifice too much.
I choose to start with 8 Fan Factor because it's the most I can do without losing either a Wardancer or a Re-roll for 1 point of FF, which obviously isn't worth it, even to a FF-happy freak such as myself. The reason I need Fan Factor is that it drastically improves your teams' winnings (due to higher gates) which is vital to a team whose players are so terribly expensive, like this one. It also helps when it's you who wins those re-rolls, pitch invasions, rocks, refs, and other Fan Factor related kickoff events, and not your opponent. Those really add up!!
I'd really love to start with an apothecary, but I just can't afford it given the circumstances above. It's always the 1st thing I buy, though!
On a side note, if you'd like to know if this strategy works, the last team I started with this method was on an on-line IRC league, the OLBBL. They started out 5-1, out-scoring their opposition 13-7, and even out-casualty-ing their opponents 12-11!