What you intended as the main thrust of your question? If so, it's really hard to pick out given the thread title and that it's just sort of tacked on the end there.
If you did just want a way to teach those sorts of skills though, boxing, kali, fencing, one stick (I can't actually find this one through google - I'm thinking around the 1900s, British naval swordsmanship sport - can't recall the name. Anyone know it?), and so on all use fairly similar systems for that which seem to work or have worked very well. There's no reason you can't steal the teaching tools off of them.
You'd teach people to throw some basic strikes really well, jabs, hooks, elbows, kicks, and to do some grappling. And then you'd create sets of paired drills, where one side would perform a very good attack and the other side would perform a very good deflection or block. You'd just do the thing to the deflection or the block, you wouldn't do any technique once you'd got it - and then it would be the other guy's turn. And you'd have them alternate those things at a high rate, introducing another attack and another defence every so often. And then you'd start mixing the different sets of drills together. Start varying how the person moved in with the attack or the defence. Just gradually increase the range of attacks and the range of entries you were using.
And then you'd teach the aikido techniques as applications that you could do from certain pick ups. "From here you can carry this forwards into such and such a technique." Perhaps even stick your techniques and associated stepping patterns into paired katas, I know some karate teachers who have joint lock katas that seem to work very well; especially since students can go away and look at how different moves and steps flow together more or less on their own. But what you'd - at least initially - spend the majority of your time on would be the pickups, the deflections, the more critical situational reflexes part of things.
From there you'd have a solid basis to feed the techniques into randori on the back of a well developed set of underlying skills.
The actual randori itself though, arguably, isn't the root of the problem here. If you just take people and throw them up against each other without the underlying skills to use their techniques they're just going to muddle through as best the situation allows them, it's going to be a mess whether you have it resistive or not. Karate people do that all the time with their sparring and it just turns their beautiful techniques into bad boxing.
Live training is not the most effective teaching tool. Certainly against a decent striker live training of a newbie would be completely pointless.
"I don't know, I just stood there and tried to do a technique and then I was looking at the ceiling."
It's one of a range of teaching tools that together work to develop varying levels and aspects of skill.
There's a level of skill required before you can start using randori - resistive or otherwise - effectively. Both on the side of the attacker and on the side of the defender. You need to address how to teach that first of all, before speculating on what it's going to look like makes any sort of sense. Because without that there are so many different directions things can go in as people try to work things out for themselves and modify what they're doing to make it more effective for the opposition that the skills they have tends to put them up against.
I'm interested, basically, in a more efficient, effective, way of teaching/learning aikido.
Regards randori: you are mistaken.
I spar excellent people in judo, and BJJ: it isn't *Start -> Guy smashes me -> The End.*. Higher grades allow you to work, and if they do 'finish you', they do it safely.
Some people do treat sparring as a win/lose situation, yes - but a lot see it as a learning tool, and are always working to refine their techniques.