When it comes to exchange yes, harass the fuck out of them, and why it's useful to get the private emails at the least of your buyer/seller. Don't bother waiting for your solicitor every day, give them a call in morning saying you give permission to proceed and ask them to start harassing down the chain, so it can come up nd back down asap. Sounds very similar to the problems I had, in the end we had to get everyone (me,my buyer, my seller, my agent and my sellers buyers agent) all harassing the fuck out of the one shite solictor, and even then we only got it over the line at 4:30pm, was by far the most stressful part of the process as was supposed to be moving on the Thursday, and only exchanged on the Monday! was 30 mins away from cancelling my movers.