Army builder files are acceptable. A good rule of thumb is if in doubt don t do it. Questions as to the relative beardyness of selections, combinations, etc. will not be answered ahead of time so please use rule of thumb. You will not be judged on how well you paint, but rather that they are painted. Painting your mini's is a part of the TTG hobby as much as playing.
Paint is what makes the models come to life on the table.
If your army is not painted then 3 pts. will be deducted from your composition score. No one wants to see a bunch of small naked unarmed goblins with a power of 8, and the ability to shoot power 6 missiles out of their ears. So with this said think Fair Representation . Again, as above, the model will need to appear to look like the force choice that it represents. It is an absolute must to show all proxies to your opponent.