Personally, I'd stop EK at 8 instead of 10. This means ranger can go to 4, which gives you a subclass at ranger 3, and a feat at ranger 4. The downside overall, though, is that the ranger spells will save/target on wisdom, and the EK ones on int. I'd probably go 2-4 levels of wizzy (Abjuration wizzy, probably) over Ranger. Every 3 levels of EK gives you a caster level, and every level of wizzy adds 1. So with 4 levels of wizzy and 8 EK, you'll get 3rd level wizzy spells. Which you will be able to know, because wizzies can scribe spells up to their caster level (whereas others are limited by their class level).
War is the more "smashing faces with hammer" domain. Light is the best debuffer (due to some gear every cleric can use, but Light has their divinity charge abilities that tip the scale in its favor). Nature has the CC, thanks to various druid spells. Tempest is good at nuking things with electricity. Two clerics can definitely work, though you'll probably feel like you get a lot more out of Shadowheart if you swap her to a different domain. Just pick one with a different focus than your main cleric. So if you go War with your main, maybe go Life, Light, or Tempest with your Shadowheart.
As far as bard/paladin goes, you start with 3 goody-two-shoes choices, but if you break your oath, you can become an oathbreaker paladin. So pick the paladin oath you want, and, well, if it doesn't mesh with what you want to do, you'll wind up an oathbreaker quickly enough
However, it does mean if you want to tweak your build, it'll be a bit more of a pain to respec, as I believe you'll have to redeem yourself first.
That said, I wouldn't worry about it too much. Just pick one and go with it. Odds are, on your first playthrough, you'll miss enough things that you'll want a second one if you enjoy the game a reasonable amount. And you'll get a ton of character ideas, and so on. And if you didn't use it the first time, there's the Dark Urge to further differentiate a second playthrough.
