Ok so I have decided to try getting my water corrected with something other than 5.2 and so have downloaded my water report from Severn Trent.
I have plugged in the values I can find on the report into GW's Liquor Treatment Calculator as so:
CO3 Reduction Method=Boiling (couldn't get rid of all the warnings using CRS which would be easier but I don't know what to do about the warnings)
Hardness 214.7 as CaCO3
Calcium 85.97
Sodium 20.25
Carbonate 128.73
Sulphate 75.92
Chloride 32.31
Which made the Ion Balance Check come out 5.17/6.78 so because magnesium is not listed in my reports I guessed that it is 19.5 which makes it balanced at 6.78.
As my main concern is more getting the liquor into a general fit state rather than fitting a particular profile I just chose General Purpose for now. So in the warnings box I get "Your target carbonate is too low. Click the CO3 button on the right to correct it" and so click it which then gives the warning "Your target mg is too low. Click the Mg/ Na button on the right to correct it" so I click that. Now I have no warnings

My Final Liquor looks like:
Calcium 103.3
Magnesium 19.5
Sodium 20.3
Carbonate 19.9
Sulphate 214.6
Chloride 89
And I get Salt Additions Required as:
Salt Additions Required Volume to be Treated: 60 Litres
CRS Required: 0 ml/l Total CRS: 0 ml
Calcium Sulphate (as gypsum): 248.55 mg/l Total Calcium Sulphate: 14.91 grams
Calcium Chloride (dihydrate): 117.38 mg/l Total Calcium Chloride: 7.04 grams
Magnesium Sulphate (Epsom salts): 0 mg/l Total Magnesium Sulphate: 0 grams
Sodium Chloride (common salt): 0.13 mg/l Total Sodium Chloride: 0.01 grams
Calcium Carbonate (as chalk): 0 mg/l Total Calcium Carbonate: 0 grams
Sodium Carbonate (soda crystals): 0 mg/l Total Sodium Carbonate: 0 grams
Sodium Sulphate (Glauber's salt): 0 mg/l Total Sodium Sulphate: 0 grams
Magnesium Carbonate (anhydrous): 0 mg/l Total Magnesium Carbonate: 0 grams
Does this all look correct?
What are the chances the report is anywhere near my actual water and if not is treating my water in this way likely to make my water worse?
What would the effect of treating my water with Campden Tablets be on the above or can I stop using them if I do the above?
Am I likely to improve my beers by doing this? What else can I do to treat my water?
Is there any real reason to add the .01 grams of salt?
Suggestions please