First off thanks for separating your paragraphs and some bold type.
Made it very easy to read.
I hope you haven't paid for the stock TD parts.
In my opinion the turbo should be a VNT-15.
They are used on the MK4 TDI engines.
The whole VNT-15 turbo and exhaust manifold can be found used for $250 or less.
It's easier to install and remove a Vinny, because those 4 exhaust manifold to turbo bolts on the stock setup are a pain.
It doesn't limit what intake you can use, because the VNT-15 sits low.
And you can remove the intake without having to remove the turbo with Vinny15.
The stock 1.6TD intake has to be a skinny thing and not easy to find for cheap.
https://vwdiesel.cokenet.org/viewtopic.php?t=9515 Turbo outpipe is easier to make since the turbo is farther to the right,
away from the shifter linkage,.. and you won't find a stock TD downpipe for a MK1 Rabbit.
OK maybe you will find one but they are very rare,.. and therefore spendy,
like a stock MK1 airbox for a MK1.
You'll need to use the stock MK2 TD airbox or go with some custom air filter setup.
The stock turbo doesn't boost very high and doesn't come on early enough.
The stock turbo won't make it feel very fast, a VNT-15 will make it feel very fast.
I run an NA pump on my TD. The Load Dependent Assist/flying saucer doesn't add more fuel,
it reduces fuel until there is boost.
It doesn't run on vacuum, it is boost controlled.
If you don't want smoke keep your foot out of it.
And since the VNT-15 brings boost so early,..
(the stock boost doesn't come on until 2000 RPM)
it clears up the low RPM smoke pretty good.
More boost makes it run cooler not hotter like a gasser.
With the diesel; black smoke means it's burning hotter.
Stuffing more air in cleans it up, cools it off.
That's why a turbo on a diesel is a given.
On a gasser you have to be careful not to add too much air or the pistons will burn.
Worst thing with too much air on a diesel is it adds backpressure on the exhaust side and steals power.
I suppose it could blow a headgasket if pushed too far but my little 1.5D, 11mm headstuds, VNT-15 held at 35psi.
Running a turbo without the oil squirters should work just fine.
My 1.5D with a VNT-15 did just fine with an NA pump and no piston squirters.
I don't like going over 1200F. At least not for very long.
No idea what kind of temps an NA diesel sees.
I've never put an EGT gauge on an NA diesel.
An intercooler would help, I want one on my 1.7TD/VNT daily driver because the EGTs get to 1350F if I keep it floored.
A TD will need an oil cooler or
stock "oil warmer" which initially warms the oil up with coolant
then uses the coolant to keep the oil cooler than the 300F+ it would be without it.
Injectors just need a good spray pattern,
to all pop around the same/proper psi
and to not leak after pressure is off.
2.25" exhaust is minimum, fits a Rabbit pretty good.