LifePO4 is supposedly "safer" than other lithium based batteries. But it still uses the same principle that all cells have to be of equal voltage or it will "blow up in your face" (figuratively of course.... but they'll smoke and catch fire and all that).
I honestly think you should get a good charger and probably not a $9.99 wall charger. At minimum I'd be looking at spending $40 on a good balance charger (that both balances the cells and charges the battery).
PS: The thing on the end are called "balance leads" not sure why that one doesn't have one but that's what they're called. But yes in short get something with a balance lead and get a quality charger. It might also be wise to get a "lipo bag" as well as some RC'er in the US set his house on fire when he was charging a damaged lipo pack.
Lipo bag like this just to be safe/for extra security (and also don't abuse your lithium based batteries): Lipo Anti-Explosion bag - YouTube