Can not delete multi shop with one test order

[lovemyseo]

Hi I have prestashop 1.6.1.6 multishop with one test order I want to delete that shop now as I want to focus on main domain , what is the best way to get that done, if I delete the order it can disturb main store as well as order are listed in order in database so deleting one can cause issue for sure .
 

Any help PS gurus
 

And is there any major difference between PS 1.6.1.6 and 1.6.1.9 ? so that I should switch , PS admin is slow as usual even though I am on VPS server 
 

http://biophoretics.com is the store