Loots from Chronoscope and IQ are all BtA. This isn't a big issue for the 1st, but the 2nd is such a grind that it's much easier with shared bank. But the most important use of shared bank is Cannith crafting: this allows to equip all your characters while leveling only one of them. Sure, there are unbound shards, but it requires a much higher level to craft the same effect. Cannith craft is worth investing for F2P, because it provides a very nice gear, some being simply unique.
As a side note, consider that the most beneficial investments for Favor are: new character slots, which allow to gain favor (and thus TP) while playing the game instead of grinding the first 100 favor points; and TRing using epic tokens (a new life = gain all this favor again), which makes epic content very important.
I agree with Stille_Nacht that low-mid level packs with no epic content is not a good investment. You really don't need it to go to 20, it's useless once you're caped, and it will give you less TP back because it won't help you to TR.