The recipe is not from a recognized research-based site.  I would be hesitant to say it is safe when comparing it to recipes from reliable sites.  I have attached a recipe for pizza sauce from the Ball Complete Book of Home Preserving.  You could add a few more dried herbs to the recipe if you like.  

I would suggest freezing the recipe you included in your question.
I don't know if there is a conversion for lemon juice to citric acid other than when adding small amounts like when canning tomatoes.  I always add a little sugar to my sauces to reduce the strong lemon flavor.  

If you have other food preservation questions you might like to call the OSU Food Preservation/Safety Hotline open M-F from
9 am-4pm. Certified Master Food Preservers are available to answer your question. the number is <personal data hidden>.

Thanks for using Ask Extension
Nellie Oehler