in a 2's, the priest can keep both targets shielded full time, as long as they dont have the weakened soul debuff. basically, this gives you 15s after a shield to pop it before having to deal with a new one.
one way to help deal with that is to make sure you stack as many damage effects at once, such as saving death wish for use with a trinket after you've procced flurry. but theres no guaranteed way of doing it really; a lot of it just depends on whether or not you get a crit off. if you do, youll more than likely break the shield. if not, you probably wont, or if you do, a new one will be back up in a few seconds.
vs any lock, check to see if they have a sacrifice bubble up, and if they do, dont engage until it wears off. thatll help a lot in the long run.
as far as pet killing goes, you need to LoS the pet as best you can and have your paladin exorcism it while you dps it. this should kill most fel hunters in under 5s, assuming at least one of you nabs a crit. voidwalkers are a bit tougher, but if the lock is using a voidwalker then theres no danger of spell lock, which gives your paladin more wiggle room.
a lot of this fight depends on your paladins ability to LoS mana burn and mana drain and fear, as well as your ability to keep both the priest and lock controlled while also getting in range long enough for the paladin to keep you up. once the lock starts life tapping things get a bit easier, since thats extra damage done essentially, and if youre pressuring the priest the entire time, then youre forcing the priest to split healing, which, if youre good enough, is what will give you the win eventually.
dont be afraid to coordinate attacks with your paladin either. now that +healing adds damage, even a fully decked healing pally can put out some mean judgements and holy shocks, not to mention hammer of wrath.
above all, dont forget that its mostly an issue of practice and counters. in 2's, some combos counter other combos, and war/pal gets countered hard by priest/lock, altho it counters war/druid pretty easily. keep at it and eventually youll both learn how to work together to the best of your ability and adapt to situations as they arise.