I'm in a casual guild, I regard myself a casual player. And it's not only a time issue but a skill issue as well, I'm at best a mediocre player (tunnel vision, slow reaction times, poor manual dexterity). I think me and my guildies adequately represent the target audience for Story Mode.
Having said all that, we tried Explosive Conflict last night and could kill the first boss(es) on the fifth try, if I recall correctly. It's actually quite an intuitive fight, the only thing that might be tough to figure out without a guide is the requirement to switch tanks every time they leap to each other. I don't have time to keep looking at my debuff bar during fights
But 1) not standing in red target markers should be elementary 2) the game warns you with BIG RED LETTERS
to stay away from Toth when he goes berserk.
It's absolutely doable, watch a quick video guide (there's a good one that is a whole 5 minutes long) if you want to speed up the learning process. I was one of the tanks, in full Columi (with crafted Rakata belt and armguards), and we could down them even after one of the healers - two Sage healers, btw, just re-learning their stuff after the nerfs - died after eating up two doses of spikes right at the end when the bosses were around 5%. No need to nerf it, it's actually a very forgiving fight as we made some mistakes during the process (me being out of range to taunt the other boss when we had to switch etc.) and still beat them.