You can enter the 152 cM figure into this tool at DNAPainter (free) to see the likely relatioinshops to the match.
https://dnapainter.com/tools/sharedcmv4"Obviously it means that no other shared ancestor has undertaken a test. "
Not Necessarily. Someone with a common ancestor of your friend and the match may have tested but just inherited different parts of the DNA - its all random. Also it depends on what site you are using i.e. a smaller site less chance of a match or a larger site more chance of a match but is the information as good eg. do they have a chromosome browser.
"Would it also mean that a shared surname may be really uncommon or few family from that line ?"
no you cannot conclude that. for example I have some rare surnames in my tree yet I have DNA matches with them but some of the more popular surnames no matches yet. Its all a lottery on who tests.
"I have traced the matched tree back to all sets of great-grand parents and their siblings to find a connection."
An immediate thought is that there is either a marriage (and offspring) that you do not know about or an affair with offspring unknown to you. I had a match for a couple of years that I could not sort out. It was only resolved when the match contacted me and told me of the second marriage of his grandmother (my great aunt) from whom he was descended.
hope that helps
