When Kohai and Nage: Seek to execute reps that are complete in detail but intense enough and with enough applied energy to expand your performance envelope in terms of tactical immediacy and power. Take advantage of your senior's higher ukemi skill by performing reps at as high an intensity as possible while never compromising any of the insights you have gained concerning good form. Do not seek to be "gentle" with your Senpai. Trust in their ukemi to keep your experiments with form and power safe for all. This is particularly true when partnered with Sensei during class. It is not rude, nor dangerous, to throw Sensei "as hard as you can".
I have to say that I disagree wholeheartedly with this. It is almost always rude and dangerous to throw anybody with full intensity...More often than not any injuries sustained in my Aikido training have come from individuals with significantly less experience than I.