Depending on the brand of spacer you are fitting you may find that you will have to remove the wheel to recheck the torque of the spacer nuts.
Torque settings will also depend on what brand of spacer you are fitting, so best talk to your supplier, however your numbers will not be far off.
Cart before the horse springs to mind.
What are the suppliers saying ?
It is bad enough that you are having to wait, however it may be a far bigger issue when you find that it is a poor fit.
May sound a bit cynical and harsh, however all very true.
Castrol SRF is the choice of the informed, but as Snjur says, expensive, however less fluid changes, so cost effective and it does what it says on the tin.
I think that you have been extremely unlucky as mechanical failure of Hosetechnic lines is almost unheard of.
However, one failure is one to many and a compensation claim would not be deemed as unreasonable.