Re: multiple opponents / ending fights
It is entirely possible to take on multiple opponents. i have seen actual footage of O'sensei taking on 4 to 5 opponents at once and none of them seemed to be able to touch him . I've also seen my sensei do it b4. Its all about having swift movements and taking your opponents momentum and using it against them . I've read articles about when O'sensei was in the japanese military and he would single handedly take on many men at once and overcome them... so it is possible
as far as ending fights goes. During aikido its not about ending a technique its about demonstrating and learning from the practice. however in real life ending a fight can happen w/out hurting someone . most likely if u have a altercation , and u pin someone and show them taht u could have hurt them then most of the time they will leave u alone . of course if they dont then it may come down to having to hurt them out of self defense. but of course this is only when its necessary . sry i may have rambled on a little too much .
hope this helps