The main thing to worry about as a F2P is getting helms on your non-cloth or non-Alliance leather/mail wearers. Else you'll be losing the armor specialization in BGs, which is 5% base stats I think. That's the biggest stat increase you're going to see (aside from using a wand as a caster). Then weapon speed. After that, ilvl.
As it is now, it's fairly hard for a F2P to push their ilvl high enough.
Here's the thing, your item level is calculated by finding the average of your gear. So, you add up every item level then divide it by how many pieces. If we do this, we can calculate that even with all warforged gear, two fish trinkets, you can only hope to get an item level of about 37, rounding up (as a "pure" F2P). With the pendent and rocks you can get much higher but I believe they're soon to be gone. Blizzard is being vigilant in fixing these items, probably due to the bracket mergers and further interest in balancing lower level PvP.
Even if you get only warforged item level 35 gear in the non-PvP crate slots (helm, shoulders, gloves, waist) then get PvP gear in the rest, with dual AGMs, you're only looking at an item level of 33.
I believe
@Lil figured out it was like ilvl 34-40-46-52?
Also, maybe
@Hashbrowns :O