Re disconnecting the pump for over 90 minutes: you don't need to take an injection, you can just reconnect the pump for long enough to give yourself a dose of insulin (either what you'd have gotten during the time the pump was disconnected, or you could do something fancier if you knew from past experience that you'd need more or less).
My diabetic son's taking chanbara not aikido and it's just an hour long, but since it's vigorous and physical (as is aikido) he always disconnects his pump. When he does something very active and lasting for a few hours, he always takes breaks every 90 minutes or so to reconnect the pump briefly and give himself insulin.
You disconnect the pump not just to keep from getting insulin while exercising but because it's an expensive piece of equipment (US$5000 but health insurance often covers most of it) and you don't want it broken. Also, if something gets caught on the tubing and yanks the pump's infusion set out of you (it doesn't hurt), you'd have to stop and put in a new one before you'd be able to get more insulin via the pump and that would be inconvenient.