After running a gasoline turbo engine for a long time before getting an AAZ, I had/have a lot to learn.
For instance, within the specs of the turbo (and head gasket) boost is safe. IE damage comes from running rich, not lean.
From my reading and experience, your turbo can probably handle up to 18 psi, though that's less than optimal for efficiency. Mine will spike to 18 but doesn't hold anything below 15. I have an intercooler.
Anyway, it's a really good idea to run an EGT gauge, if you're messing with fueling. Consider grabbing one.
Also, changing the nuts on the wastegate rod is less than ideal. Get a manual boost controller -- it's a valve that can be had for under $30.
You might start by disconnecting altogether the vacuum line to the wastegate. With stock fueling, you might not reach a very high boost level! Until I installed a performance pump, I never saw more than 12-15 psi. Just, of course, be very careful driving with the wastegate disconnected, that you don't push the turbo too hard.
Once you see the maximum boost your fuel level will permit, you can either use the boost controller to set a reasonable boost, or turn up the fueling, and then set the boost controller.
Unlike on a gasoline engine, and contrary to what you were saying, you may need to increase fuel to raise boost.
So, anyway, there's a bit of back and forth between fueling and boost. Obviously you need a boost gauge and it's a really good idea to have an EGT gauge! (I wouldn't want to touch fueling without one.)
I had a pump with a 1.6td boost pin, which pushed too much fuel for my K03. I saw a significant amount of smoke under boost. Give it a try and see what happens. You will likely need to change your fuel setting and maybe boost.
I have a vanagon and likewise would prefer not to blow up my transmission, but I tuned my motor for as much power as possible with reasonable EGTs. Indeed, it's tuned such that my EGTs can get dangerously high under certain circumstances -- but I control it with the fuel pedal. Nobody else drives my van! Anyway this allows me to have as much power as possible when I might need it. I have a digital EGT gauge with a buzzer set to sound at I think just over 1300. It only goes off at highway speeds, up grades, at full throttle.
This approach might not make as much sense for you. My vanagon is a lot heavier than your Samurai and I need all the power I can get. You probably don't