You’re welcome 
Yes, SR is the best way to farm nemesis MIs. Except Kaisan amulet, you need to target farm that nemesis to acquire that. But some other MIs, especially that can be acquired by one monster can be target farmable in main campaign. And also you can’t get some roguelike dungeon MIs from SR.
Best and fast way to farm SR is doing two shards then get reward like ultimate 65-66 and repeat. You can also farm SR in normal/veteran or elite to be faster and higher levels. Shattered Realm Loot Table Check here for efficiency.
Yes energy regen and spirit bonus is no big deal but you need OA and that 5 green affinity bonus. Other options cost you second node of ‘‘Ulzuin’s Torch’’ which provides %5 OA and %15 Chaos Resist. So you’ll lose %8 OA in total which is huge. But if you reach 2900ish OA or something with the MIs; then you can get ‘‘Scholar’s Light’’ + 1 Green Crossroads which grant you some elemental and aether resistances or ‘‘Fox’’ for extra %4 lifesteal.
So it depends on the amulet and shoulder rolls you’ll get. As I said slow resist is crucial and try to craft another serenity for different rolls; %attributes does not grant you much. Resistances or even stun/freeze resist would be much better.