One could always take a set of hubs to a machine shop and have them make a new set of blank ones then drill them to 4x100, if money is not the issue that is
Or better yet, have them made out of a higher grade of metal than normally used, make them thicker at the flanges or just the area for the studs, then machine off excess metal to get the wight back down........
Less expensive is to have the stock holes filled by somebody that knows enough to do it right.
But, properly done, drilling holes can make some parts actually stronger than weaker but I am not the one to figure that out on something as important as a hub, I just know there is plenty of material to do a 90 degree rotation and drill new holes and not worry about it in the least.
-------------
I can understand being apprehensive of some mods on a long term car on bad roads, makes sense, why the very first mod I would do is go to 15 or 16" wheels, 15's over 16s for less weight and more sidewall, low weight strong wheels also protect the suspension including the hubs and the chassis.
Sticking with 17" wheels on bad roads instead of going to smaller diameter wheels makes no sense to me at all.
-------------
I mentioned earlier about pounding over the curbs on the track, two track days is all this car has seen, nearly all the rest of the miles are from tune runs and cruising. I rarely play on the streets and no longer track the car due to an eye injury I could work around but I like to go all out all the time on track and I do not feel quite safe now doing so and I have decided I am done with major car builds, getting into rock hounding, full time RVing, eventually land up in the hills for off the grid living, the car no longer fits my needs but have not tried very hard to sell it as still love it and my wife wants me to keep it
WHEN I was tracking any car I did a very high level of maintenance inspecting ever serious nut and bolt, hoses, fluids, etc after every single event, I even re torque the lugs after every session and I carry a well sorted out tool kit at all times on the street.
All that said, a 4x100 conversion is still one of the best moderate to very low cost mods one can do on this car, one of the very first things I did in the 8 months it sat on the lift with 293 miles on it. Those that choose not to do this mod have their reasons but I would not let that sway me in the least, this one was such a simple no brainer mod I would personally feel a bit foolish if I did not do it
Rick