Slight spoilers, obviously. I personally like the Destroy ending best, but you'll get a different result from it depending on your EMS. If it's high enough (I'm not sure of the exact parameters) you'll knock off everything synthetic and that's that, but if it's too low the impact of the Crucible blast will kill a heap of organics too. I had around 3150 for my first playthrough (with the extended cut), and it basically implied that if I picked Destroy I'd pretty much detonate the whole universe and effectively do the Reapers' job for them. Ended up going with Control instead, which sucked.
I've been dual wielding for so long now I struggle to play any other way. I tend to find using two swords best as you swing fast enough that the lack of block doesn't really become an issue. But yeah, I guess it's all down to personal preference and magic isn't my strong suit at all so if you're into that, go for it. Same with 2h. Try everything and see what you like.