So, in an upcoming league/campaign game at my LGS, I'm going to be facing Blood Angels with my Chaos Space Marines.
Now, a couple things worth noting:
As mission Special Rules, there will be no Psykers, and all attacks are made at +1 Strength. (ALL attacks. Including exploding vehicles and other random stuff like that.)
Additionally, I only use Nurgle and Khorne, or unmarked. No Slaanesh, no Tzeentch.
So, having not played Blood Angels, what should I expect?
The main issue I had the last time I used Chaos Space Marines against Blood Angels was when he outflanked a Baal Predator right behind my 20-strong CSM squad. A single Str 6 AP3 template wiped out most of them before I could do anything about it.
The only defence against something like that is to keep the more vulnerable units away from the flanks if you know they have one of those in reserve, then make it your top priority when it does appear.
The +1 Str to everything sounds interesting, it'll make vehicles a bit more vulnerable but most of your units can still rely more heavily on armour saves.
One thing I might suggest is Defilers, Battle Cannons are great against MEQs and vehicles, especially since they'll outrange almost everything else, and a +1 Str Reaper Autocannon will complement it well against T4 Marines. Blood Angels might also opt to charge in early and being forced to strike front armour may hinder them a bit.
Given the +1 Str of all weapons, Marks of Nurgle could really come into their own here however I'll remind you to keep an eye on the cost.