Per,
It all seems potentially to be going the wrong way.
If only one journal is damaged and you are trying to rectify the crank by grinding one journal you will need to be very careful.
Depending on how the damage has occurred I think you will need to check carefully that the crank is still straight particularly if there is any 'blueing' of the journal.
There are several techniques used for repairing journals.
TIG welding is used to repair damage such as gouges which are localised.
Submerged Arc Welding is more commonly used to re-surface journals and sometimes metal spraying could be considered.
If the crank has deformed when it was damaged the Submerged Arc process is likely to allow these stresses to relax and this could increase the distortion.
Crankshaft Welding
After welding some form of stress relief may be a good plan but this would be a relatively low temperature process compared to annealing which would almost certainly cause significant deformation and even in a vacuum wouldn't be good for the surface of the remaining journals.
If you grind it carefully and if it hasn't 'bent' then I am not sure you need to re-balance.
If you have to grind it correct some bending them you will need to check the balance.
The cost of 0.5 oversize Rod bearings here in UK is about $250 a set.
Good used 3.2 Cranks make about $1000 each.
If you do the re-grind and Tuftride it isn't a great deal different, the only issue is the time to find a good crank and the risk that it isn't perfect when it arrives.
I would have to say that my inclination would be to do it 100% correct or change it for another crank.
You find 3.2 cranks on EBay Germany that need a 0.25 re-grind for 700 Euros so your crank must still have some value.