I agree that the Binding shadow amp is too powerful for the reasons that Gingivitis states. Also be very mindful of potential impacts to gameplay and flow: it would be very unbalancing if a player had to narrate and roll for not only the magician but three extra spirits as well. That gives the player too much to do to the detriment of the other players, unless the character has the Spirit Trust amp and is using it to share spirits with the other players. That's a potentially fun scenario, but I'm not sure I would build a rule specifically for it.
As for the rest of the proposed rules, I understand the desire to make spirit powers more consistent between SR5 and SRA, but the net effect is to add powers and functionality which make spirits even more formidable than they already are. Per my post in the House Rules thread, I still think spirits are ridiculously good, so much so that average spirits are basically free Prime Runners, with attack pools and dodge pools that mirror maxed-out PCs. (Between attribute points, racial bonuses, and attributes starting off at rating 1, Primer Runners have 27 attribute points. An "average" spirit has 31-33. Great Form spirits would have 41-43.)
Let's look at the sample characters. Coydog rolls 15 dice to summon air spirits. That should be enough to regularly summon Great Form air spirits if they are rolling 10-12 dice to resist, especially if - as Gingivitis points out - ties go to the summoner. Plus, since there's no drain mechanic, there's basically nothing from stopping rerolls until the character succeeds. So, that gives Coydog a great air spirit with 15 dice to attack, 20 dice to dodge (!), and immunity that shrugs off the first 5 boxes of every non-magical hit. That's the current state, and to that these rules suggest adding Accident, Concealment, Movement, and Search powers.
Honest feedback: these rules are too generous without some major limiting mechanic - either Drain or only one summoning attempt per scene - to help keep summoning in check.
