Since your solicitor has no access to detailed 'before' and 'after' plans of the property (in relation to the removal of the chimney breast) there's absolutely no reason why he should even know that it's been removed unless the vendor declares the fact. (If anyone should spot the fact that it's been removed it would be your surveyor, not your solicitor). So it's clearly unreasonable to expect your solicitor to tell you something until he's made aware of it.
The searches that solicitors carry out are in relation to such things as planning permission for the council to build a major road next to the property or whether the property is within (or or likely to become within) a designated Conservation Area (which might, for example, prevent you from having a satellite dish on the property):
http://www.reallymoving.com/first-time-buyers/the-buying-process/what-are-searches-when-buying-a-house