'Ignition Setup'
I keep distributor only for distribution. I use Hall sensor on crank as a trigger input for the VEMS.
Q: So actually I have to lock the plate in the distributor and remove the vacuumline in order to lock the vacuumadvance and let the distributor only distribute the spark?
A: With the distributor used only for spark distribution, and not timing advance, none of what you described is necessary. The poles in the rotor cap are fixed, that is all that matters for spark distribution.
Q: Do I need a triggerwheel or can I just bolt on two magnets 180° separate on the standardcrankwheel?
A: With many auxiliary belts (air conditioner, servo steering, ..) this can be a problem to fit correctly. The main concern is that it must be rock solid and accurate, and be appropriate for the sensor you will use with the trigger solution. With a good Hall trigger (Honeywell GT1 is recommended) you don't have to use magnets, two slots or fields in a ferrous material is all that is needed and can be fastened in many ways depending on how the stock crank pulley is designed. In this day and age of cheap digital cameras, pictures still speak more than a thousand words, so get some snapshots.
OK here is a pic from the crankpulley:
This is how the engine looks on the output side of the crankpulley: 
TODO: fabricate trigger setup with Hall sensor on original crankpulley
I have setup the wheel with two bolts 180° separated and +- 60°BTDC.
Config
- How do I determine the correct amount of degrees the trigger passes the sensor before the crank reaches TDC?
- remove a sparkplug so you can measure the piston height with a screwdriver or micrometer gauge. Rotate the engine slowly
- with wrench, from the crank (not cam!)
- or by moving the car, in gear 5
- remove a sparkplug so you can measure the piston height with a screwdriver or micrometer gauge. Rotate the engine slowly
Measure the white dot (paint one if there is none) position precisely, and the trigger position only roughly. The dot is 0..10 degrees BTDC, quite easy to measure. This allows you to adjust the ign_tdcdelay with a TimingLight.
You can also use permanent marker pen and use length-measuring tool (eg. at the circumference of a wheel) and calculate degrees.
OK thanks I will do that.
Here is my starting config and tables with a few questions in it: