Second point. You seem to think your seniors "have it" but you don't because you can't handle attacks from non aikidoka. How often have you seen your seniors in a similar situation to what you've been experimenting with. You may be surprised that they don't fare terribly different - iow stop beating yourself up about it, it's probably not an issue with you at all.
I was wondering about this as well - how do your seniors handle resistance? One way to find out is to give them some (with a willing senior) and see what kind of solutions they will use. Could be a way to really learn something. If, on the other hand, they don't have any solutions (other than "don't resist")...well, in that case you shouldn't be surprised that you didn't know how to handle a resisting partner either. But you might want to look for somewhere else to train if that is the thing that you are after. But hopefully they will have ways to handle resistance, and you get an opportunity to learn something new.