I didn't mean to scare you. By "and use it [torque] frequently" I meant seriously high stress use. I did not mean fast highway driving, occasional auto crossing, or fun on twisty roads. With that, I should also say that I've heard of only one or two people who have had stub axle failures so it can happen. I think after you clean up your stub axles, they will be fine for use on the street and auto crossing. You could have them checked by a machine shop to make sure they are good. New ones are also available. If you are going to track your car, you would probably want to upgrade them.
For what it's worth, and it's probably not much, I still have the stock stub axles (though I know mine's history and age). My engine tops out at about 130 ft-lbs of torque. Upgrading the stub axles is a future project I'm seriously considering but for now I feel pretty confident in what I have. I don't track my car and haven't auto crossed it so far but I might. I don't go crazy on the street but I do like to lean on it a bit from time to time. The reason I am planning on upgrading the stub axles is just for added peace of mind and to strengthen a weak point.
There are other stub axle upgrades you could consider if you have worries. This one (
http://lotus-europa.com/manuals/misc/suspension/aubin.html) involves converting a Corvair stub axle and this one (
http://lotus-europa.com/manuals/misc/suspension/BMW%20STUB%20AXLE%20AUG%202005.html) involves converting BMW stub axles. Finally, this one (
https://www.prevanders.net/europa/rearaxle.html) which appears to use a modified "standard" axle of some description. The website says that the builder's email address is email address is davea42 at linuxmail.org. Unfortunately, that car was sold a while ago so he may no longer have information and there's not guarantee that that email address is still good but it would be worth a try. It looks like a pretty economical way to get a stouter axle setup.