Richards advise is good but it won't make a blind bit of difference, there is no quick fix when it comes to self-confidence.
but it does'nt matter, I've dealt with lots of people who had poor comunication skills, I did'nt think any less of them. some people are smooth & smarmy, some are down to earth & honest (try and be the latter)
the best thing to do is be prepared and talk with knowledge about the contract you are bidding on. visit all 4 pubs and take note on what each one requires, talk to the landlord about any specific problems let the interviewers know you've invested your time into giving them the best service available.
Mike