Well here we go AGAIN
Inherently there is risk in life. All the folks (no slight exaggeration) I see in this country who go out walking at night in winter, wear dark clothes so motorists won't see them.. It's the council's fault for not having enough street lighting! What on earth is he on about I hear?
If we suggest that these things we make have a roll bar, are you (whoever "YOU" is) prepared to put your neck on the block, and say this is a safe design? If not, then don't suggest it. If you are, and someone who does get hurt, comes back and says "I did it like X said, but I got hurt, so it's their fault" then you would, literally carry the risk, PERSONALLY, sorry, but that's a fact.
Make a rule, you are the one who will ultimately carry the risk.
I am happy that my column might collapse some. Is it enough? I have no idea, and I won't give anyone any measurements.
Roll bars, IMHO no chance. I won't suggest, us or n any way be involve, and a few of you know the industry I'm in. Today I was looking at some of our safety gear that withstood 140 mph sideways into a bank that stopped inside 4 inches, and the driver got out a little bruised. Is ANY of our gear at work appropriate to CKs. not at all.
You are welcome to think about things that don't make your risks greater. For all the reasons in the world, keep it personal, NOT rules.
Helmet, yes, long sleeves yes  (overalls maybe), shoes definitely, goggles/visor, probably, gloves of some sort, good idea (you won't stop your self putting your hand down).
In my very honest opinion, leave it to the individual.
I honestly believe, if you think you have "stuff" to make your self safe, you will push the limits, TOO FAR! And that will kill the hobby before it hurts folks.

My thought is that a roll bar will be totally out of character in every sense. We are emulating the look and feel of pre-war race cars for a reason.
As already stated, individuals need to drive within their own competence and by relying on the additional built-in safety of a roll bar, this just leads to ill-placed over-confidence.
It's up to the individual, but I vote against it. And I see no need to progress any generic designs Chris? As long as engines stay within guidelines, and cars are as light as possible, risk of serious injury is reduced.
I am looking forward to meeting up with new members and having a run-around. Yes there will be some friendly
rivalry hopefully, but there will be no race-winners' podium.