Thus far, I've had rather bad luck when it comes to reward bags giving AE2 things, I think the earliest I got some useful things was just after Rotunda, for the most part, I just kept getting weapons & tools from bags, a couple of 1k Drives notwithstanding. That, and I like to ensure I have a "stable" (and, preferably, self-sufficient) power supply before getting into AE2 as I've gotten distracted in the past to the point where my power supply has died because I didn't throw more fuel in to a generator, and because I didn't have access to my stuff...
Also, you need the Inscriber Presses to really do much of anything outside of what reward bags get you, and you get those roughly around Inclusion Chamber^4, if I'm remembering right.
Besides, I'm a bit of an "old-school" player in that I prefer traditional item/block storage up to a point where I'm really hard pressed to store things in an organized way, then I'll start looking into alternative storage methods.
Fill the reactor with cryothium and you are pretty much set for life as far as power goes on this map. I just cleared (as in 100%, everything of value looted and everything else lit up, I take my time) Inclusion Chamber^4 and have been making a lot of diamonds and such up to this point using hundreds of millions of RF and my reactor is at 98% fuel still, I haven't added any to it and haven't used any other power source. The AE system could run for decades off that power. I understand wanting to be self sufficient and having a fuel source that will never run out, I was worried about that at first myself, but really the reactor is there to be used and honestly you don't have to worry about it at all, and you want to use it because you need the byproducts for crafting stuff.