I have tried a few different oils for pre shave and Proraso pre shave cream, none of which did anything for me. You are just starting out and developing your technique which seems pretty good as you suffer only occasional mild rawness. If you can live with the odd bit of rawness maybe just keep refining your technique till that too goes away. That way you will know your technique is good and not a poorer technique being masked by a pre shave product. Anyway, that is another way to look at it but the choice is yours.

Bob