It appears like you may have received a poor service and poor value for money with the air tightness test.
Did the 'guy on a laptop' not spend time with you to ensure you understood the significance of the findings in relation to priorities and how best to address the issues uncovered based on your plans & budget and did he address your future likely ventilation needs to ensure good air quality?
In the report you got, what result does it give for your air tightness? You will find this reported as either the q50 in m3/hr/m2@50Pa or n50 in ACH.
Don't let the availability of government grants drive what improvements you make and where you invest. Figure out first what you want to achieve (for example a warmer, more efficient & healthy home), how best to get there from where you are now and then if a grant is available for a particular improvement measure identified, great, avail of it. Too often, expensive grant aided measures are shoehorned into projects with little to no benefit to the homeowners.
Btw, the BER is not a test of the house as such but is more like a rating system (box ticking) based predominately on the age of the property and, in my experience for existing housing, is generally not worth the paper it's written on.