I'm also hoping this format is for Relena's events only, for now. After I collected cards for a good salvo team T_T they suddenly became useless as regular Salvo teams no longer works even in normal AEH.
I like it, but only as it's own event. I don't like having to use my Salvo cards all the time, as it gets too mind-numbing. Heck, we see what happens when people realize Overkill cards and stuff doesn't work well in Training and Bounty, so it's a good way to refresh our minds on what cards to keep and use. But it would mess up normal events if it were to make its way to regular EH.
I think the improvements are simply to add the custom skill materials so we can get them regularly. No change in difficulty, just trying to squeeze in the new features somewhere.
No worries. LR Union is kinda weird in that there seems to just be one thor skill that activates if you have 1 LR card in-deck. I have 16 LRs in my Thor deck now and don't see a LR Union alpha or anything more than that same 20%.
I just took an average of approximately what it costs for 2 guaranteed UR and 3 guaranteed UR on a point card step up. It's meant to convey magnitude (like it costs hundreds to get a GUR from summons) rather than being a mathematically precise value.